Free calculators
Simple tools
for everyday problems.
241 calculators for money, business, home and everyday decisions. Figures are estimates, not professional advice.
Type a keyword. Categories below stay for browsing.
Home Improvement
Block CalculatorEstimate concrete blocks needed for a wall including waste.Brick CalculatorEstimate bricks needed for a wall including waste.Carpet CalculatorEstimate carpet area, waste and roll length to order.Cement CalculatorEstimate cement or concrete-mix bags from volume.Concrete CalculatorCalculate concrete volume and bags.Decking CalculatorEstimate decking boards and packs from deck area and board width.Fence Panel CalculatorEstimate fence panels from run length and panel width.Fence Post CalculatorWork out fence posts from run length and post spacing.Flooring CalculatorCalculate flooring area, waste and packs to buy.Gravel CalculatorEstimate gravel volume and bags for paths or drives.Grout CalculatorEstimate grout needed from tile size, joints and area.Gutter Capacity CalculatorEstimate roof runoff flow and compare it to gutter capacity.LED Replacement Savings CalculatorCompare running cost of an old bulb with an LED equivalent.Laminate Flooring CalculatorEstimate laminate planks or packs from room area and waste.Lighting Lumen CalculatorEstimate total lumens needed for a room.Moulding CalculatorEstimate moulding length and sticks from perimeter and openings.Paint Quantity CalculatorCalculate how much paint you need for a room.Patio Slab CalculatorCalculate patio slabs needed including waste.Radiator Size CalculatorEstimate radiator output from room volume and room type.Roof Pitch CalculatorConvert roof rise and run into pitch ratio, degrees and percent.Roof Tile CalculatorEstimate roof tiles from area, coverage and waste.Sand CalculatorEstimate sand volume and bags for beds or screed.Skirting Board CalculatorEstimate skirting length and packs from room perimeter and openings.Tile Adhesive CalculatorEstimate adhesive bags from tile area and coverage rate.Tile CalculatorCalculate tiles for a floor or multiple walls, including waste.Underlay CalculatorEstimate underlay rolls from floor area and roll coverage.Wallpaper Roll CalculatorEstimate wallpaper rolls from wall size, roll size and pattern repeat.
Everyday Money
Appliance Running Cost CalculatorEstimate electricity cost per day, month and year.Bill Split CalculatorSplit a bill with tip — add people and share weights for an uneven split.Bulk Buying Savings CalculatorSee if a larger pack is actually cheaper per unit.Cost Comparison CalculatorCompare two purchases over their useful life.Cost Per 100g CalculatorCompare food and product prices by weight.Cost Per 100ml CalculatorCompare liquid products by price per 100ml.Cost Per Bath CalculatorEstimate water and heating cost for a bath fill.Cost Per Dishwasher Cycle CalculatorEstimate electricity cost per dishwasher cycle.Cost Per Dryer Cycle CalculatorEstimate electricity cost for a tumble dryer cycle.Cost Per Serving CalculatorCompare food by cost per serving.Cost Per Shower CalculatorEstimate water and heating cost for each shower.Cost Per Use CalculatorHow much does each use actually cost?Cost Per Wash CalculatorEstimate electricity and detergent cost per washing-machine cycle.Discount Stacking CalculatorApply multiple percentage discounts in sequence.Monthly to Annual Cost CalculatorConvert a monthly cost into yearly, quarterly and weekly equivalents.Percentage Points CalculatorConvert a change between two percentages into percentage points and relative %.Price Decrease CalculatorApply a percentage price cut and see the new amount and saving.Price Increase CalculatorApply a percentage price rise and see the new amount.Price Per Item CalculatorDivide a pack or project cost into a clear price per item.Reverse Discount CalculatorFind the original price from a sale price and discount percent.Shared Expense CalculatorSplit a bill between people with an optional tip.Subscription Cost CalculatorAdd each subscription to see weekly, monthly and yearly spend as one total.Tip and Split CalculatorAdd a tip to a bill and split the total between people.Unit Price Comparison CalculatorCompare two products by unit cost.
Business
Ad Spend Profit CalculatorModel advertising profitability after costs.Automation ROI CalculatorCalculate return from time-saving automation.Break-even Price CalculatorFind the minimum viable selling price.Break-even ROAS CalculatorFind the minimum viable return on ad spend.Break-even Revenue CalculatorFind the sales revenue needed to cover fixed costs.Break-even Scenario CalculatorModel price, volume and cost changes.Break-even Units CalculatorFind units required to break even.Cash Conversion Cycle CalculatorCalculate CCC from inventory, receivables and payables days.Coupon Profit CalculatorSee profit left after a coupon or voucher discount.Customer Acquisition Cost CalculatorCalculate CAC from marketing spend and new customers.Customer Lifetime Value CalculatorEstimate LTV from spend, frequency and margin.Discount Profitability CalculatorModel how a discount hits margin and volume needed.Distributor Margin CalculatorSplit margin across wholesale, distributor and retail prices.Employee Downtime Cost CalculatorEstimate the staff cost of downtime from headcount, rate and hours.Free Shipping Threshold CalculatorFind a profitable free-shipping order value.Gross Margin CalculatorCalculate gross margin from cost and price.Inventory Carrying Cost CalculatorEstimate annual inventory carrying cost from stock value and carrying rate.Inventory Turnover CalculatorCalculate inventory turnover and days of inventory from COGS and stock.Invoice Payment Impact CalculatorEstimate the cost or saving of paying an invoice early or late.LTV to CAC CalculatorCompare lifetime value with customer acquisition cost.Markup vs Margin CalculatorExplain and convert markup and margin.Meeting Cost CalculatorCalculate the staff cost of meetings.Minimum Order Quantity CalculatorEstimate MOQ from setup cost and contribution per unit.Payment Fee CalculatorEstimate card or payment-processor fees on a sale.Product Profit CalculatorCalculate true profit after costs and fees.Reorder Point CalculatorFind when to reorder stock from demand, lead time and safety stock.Retail Price CalculatorSet a retail price from cost and target markup or margin.Reverse Margin CalculatorFind the selling price needed for a target margin.Safety Stock CalculatorEstimate safety stock from demand variability and lead time.Shipping Cost Per Order CalculatorSpread carrier costs across orders to get a true per-order shipping cost.Time Saved CalculatorValue time saved from a process improvement or automation.VAT Inclusive / Exclusive CalculatorAdd or remove VAT from a price at a rate you choose.Wholesale Discount CalculatorApply a wholesale discount to RRP and see margin left.Wholesale Price CalculatorSet wholesale pricing from costs and margin.
Ecommerce
Amazon Profit CalculatorEstimate Amazon seller profit from user-entered fees.Bundle Pricing CalculatorPrice a product bundle from component costs and a target margin.Buy One Get One CalculatorWork out effective price and discount on BOGO-style offers.Etsy Profit CalculatorEstimate Etsy seller profit from user-entered fees.Fulfilment Cost CalculatorAdd pick, pack, postage and storage into per-order fulfilment cost.Import Duty Cost CalculatorEstimate duty, VAT and landed import cost from quoted rates.Marketplace Fee CalculatorCompare two selling-platform fee structures on the same sale.Product Landed Cost CalculatorInclude freight, duty and fees in unit cost.Product Pricing Scenario CalculatorModel price, volume and margin scenarios.Return Rate Profit CalculatorModel expected profit after returns on each order.Shopify Profit CalculatorEstimate Shopify store profit from user-entered fees.Subscription Pricing CalculatorSuggest subscription price from cost to serve and target margin.Wholesale Break-even CalculatorFind units to sell at wholesale price to cover fixed costs.eBay Profit CalculatorEstimate eBay seller profit from user-entered fees.
Personal Finance
Billable Hours CalculatorTurn capacity and utilisation into billable hours and revenue.Car vs Bus Cost CalculatorCompare annual car running costs with bus and occasional taxi.Car vs Train Cost CalculatorCompare commuting by car and train.Commute Cost CalculatorCalculate total commuting cost per week, month and year.Commute Time CalculatorEstimate one-way and weekly commute time from distance and speed.Cost Per Mile CalculatorCombine fuel, parking and other trip costs into a per-mile figure.Day Rate to Salary CalculatorConvert a contractor day rate to a salary equivalent.Effective Hourly Wage CalculatorFind your real hourly wage after unpaid extras.Electric vs Petrol Car Cost CalculatorCompare yearly energy cost of electric and petrol cars.Freelancer Minimum Rate CalculatorCalculate a sustainable freelance day and hourly rate.Freelancer Utilisation CalculatorCalculate billable utilisation percent and a target rate from desired income.Fuel Cost CalculatorEstimate fuel cost for a trip from distance and economy.Hourly to Salary CalculatorConvert an hourly rate into annual salary.Lifetime Commute CalculatorEstimate years of commuting time from daily travel and career length.Monthly Payment Comparison CalculatorCompare two financing options.Mortgage Overpayment Savings CalculatorEstimate interest saved by overpaying a mortgage.Night Shift Pay CalculatorCalculate night-shift pay with an uplift or flat night rate.Overtime Pay CalculatorCalculate overtime pay at a multiplier of your base rate.Part-time Salary CalculatorPro-rate a full-time salary to part-time hours.Pay Rise CalculatorCalculate a new salary after a percentage pay rise.Salary to Day Rate CalculatorCalculate a freelance-equivalent day rate from salary.Salary to Hourly Rate CalculatorConvert an annual salary into an hourly rate.Take-home Pay Comparison CalculatorCompare take-home pay at two salaries using your own deduction rate.Weekend Pay CalculatorCalculate weekend shift pay with a premium multiplier.
Food
BBQ Meat CalculatorEstimate meat weight to buy for a barbecue guest count.Baker's Percentage CalculatorConvert baker's percentages into ingredient weights from flour.Buffet Quantity CalculatorEstimate buffet food weight from guests and grams per person.Cake Serving CalculatorEstimate cake servings from tin size or portion style.Cake Tin Conversion CalculatorScale a cake recipe between tin sizes by area.Coffee Ratio CalculatorBrew coffee from a coffee-to-water ratio and dose.Cold Brew Coffee CalculatorScale cold brew concentrate from coffee dose and ratio.Cupcake Quantity CalculatorEstimate cupcakes from guest count and cupcakes per person.Party Food CalculatorEstimate party food portions and packs from guest count.Pasta Portion CalculatorEstimate dry pasta to cook from servings and grams per person.Pizza Dough CalculatorScale flour, water, salt and yeast from baker's percentages.Recipe Cost CalculatorTurn ingredient spend into cost per serving.Recipe Scaling CalculatorScale named ingredients up or down for a new serving count.Rice Portion CalculatorEstimate dry rice from servings and grams per person.Sourdough Hydration CalculatorCalculate water for a target dough hydration and flour weight.
Gardening
Compost CalculatorEstimate compost volume to improve soil over a bed.Drip Irrigation CalculatorEstimate weekly water volume from emitters and run time.Fertilizer CalculatorEstimate fertilizer from area and application rate.Garden Area CalculatorCalculate garden or lawn area from length and width.Garden Bed PlannerPlan bed area and plant count from size and spacing.Garden Soil CalculatorCalculate soil volume for a bed.Greenhouse Size CalculatorCalculate greenhouse floor and shelf growing area, plus plant capacity.Irrigation Flow CalculatorEstimate irrigation flow and run time for a target volume.Lawn Seed CalculatorCalculate grass seed from lawn area and sowing rate.Mulch CalculatorCalculate mulch volume and bags for a bed depth.Plant Spacing CalculatorWork out how many plants fit in a bed at a given spacing.Raised Bed Soil CalculatorCalculate soil volume and bags to fill a raised garden bed.Topsoil CalculatorCalculate topsoil volume and bags for a bed or lawn.Vegetable Plant Population CalculatorEstimate plants from bed area and spacing in rows.
Craft & Making
3D Print Cost CalculatorInclude filament, electricity and machine time.3D Print Electricity CalculatorEstimate electricity cost for a 3D print from watts and time.Board Feet CalculatorCalculate board feet from thickness, width and length.Board Spacing CalculatorSpace deck or fence boards evenly across a span.Crochet Gauge CalculatorConvert a crochet swatch into stitches per 10 cm and project width.Fabric Meterage CalculatorEstimate fabric metres from pieces, length and width.Knitting Gauge CalculatorConvert a knitting swatch into stitches per 10 cm and project width.Miter Angle CalculatorFind miter saw angles for frames and equal-sided polygons.Quilt Backing CalculatorEstimate backing fabric from quilt size and fabric width.Quilt Binding CalculatorEstimate binding strip length and fabric from quilt perimeter.Resin Print Cost CalculatorEstimate resin 3D print cost from volume, resin price and electricity.Seam Allowance CalculatorAdd seam allowance around a finished piece size.Shelf Bracket Spacing CalculatorSpace shelf brackets evenly along a shelf length.Skein Requirement CalculatorEstimate yarn skeins from project metreage and skein length.Yarn CalculatorEstimate yarn skeins from project metreage and skein length.Yarn Substitution CalculatorRecalculate balls when substituting a different yarn yardage.
Creative Tools
Aspect Ratio CalculatorSimplify width and height into a clean aspect ratio.Book Cover Dimensions CalculatorWork out full cover flat size from trim, spine and bleed.DPI CalculatorFind DPI from pixel dimensions and print size, or pixels needed for a target DPI.Image File Size EstimatorEstimate image file size from pixels, bit depth and compression.Image Resize CalculatorScale image dimensions while keeping aspect ratio.Labels Per Sheet CalculatorCount how many labels fit on a sheet with margins and gaps.Large Format Print CalculatorCheck effective DPI at a target print size, and the largest size that still meets a minimum DPI.Photo Crop CalculatorFind centered crop size for a target aspect ratio.Print Bleed CalculatorAdd bleed to document dimensions for print-ready artwork.Print Size CalculatorConvert pixel dimensions and DPI into print size.Social Media Image Size GuideLook up common social post, story and thumbnail pixel sizes.Spine Width CalculatorCalculate book spine width from page count and paper thickness.Sticker Sheet CalculatorFit stickers onto a sheet with margins and gaps.Timecode CalculatorAdd or subtract video timecode at a chosen frame rate.Video Bitrate CalculatorEstimate video file size from bitrate and duration.Video File Size to Bitrate CalculatorFind the bitrate needed to hit a target video file size.Video Upload Time CalculatorEstimate upload time from file size and connection speed.YouTube Thumbnail Size CalculatorGet YouTube thumbnail pixel size at 16:9 and scale custom widths.
Design & Colour
Accessible Colour Pair GeneratorCheck WCAG contrast and suggest a stronger pair.Analogous Colour GeneratorGenerate analogous neighbours from a base hex colour.Brand Colour CheckerCheck a brand hex against white and black for contrast.Colour Palette GeneratorBuild a simple palette from a base colour with complements and analogues.Colour Shade GeneratorGenerate lighter and darker shades from a hex colour.Complementary Colour FinderFind the complementary colour opposite on the colour wheel.Contrast CheckerCheck WCAG contrast ratio between two colours.Gradient GeneratorBuild a CSS linear-gradient from two colours and an angle.Gradient Midpoint CalculatorFind the midpoint mix of two hex colours.HEX RGB HSL ConverterConvert a hex colour into RGB and HSL values.HEX to Closest Named ColourMatch a hex colour to the nearest common CSS colour name.Interior Colour Palette PlannerSuggest accent and trim colours from a wall hex and undertone.Monochromatic Palette GeneratorBuild a monochromatic lightness palette from one hex.
Education
Final Grade Needed CalculatorCalculate the mark required on a remaining exam.GPA Calculator (Grade Point Average)Calculate weighted Grade Point Average (GPA) from grade points and credit hours.Grade Percentage CalculatorConvert marks earned into a percentage score.Reading Time CalculatorEstimate reading time from word count and reading speed.Study Time CalculatorSpread study hours across days until an exam or deadline.Weighted Grade CalculatorCombine coursework scores with different weights into an overall grade.
Events
Event Budget CalculatorEstimate event spend from guests and line-item costs.Event Seating CalculatorEstimate seating capacity from room size and space per person.Party Drinks Quantity CalculatorEstimate drinks to buy from guest count and drinks per person.Party Invitation CalculatorEstimate expected guests from invitations and attendance rate.Wedding Food CalculatorEstimate wedding meal portions from guests and service style.Wedding Table PlannerWork out how many tables you need from guest count and seats per table.
Travel & Practical
Currency Budget CalculatorConvert a travel budget at a user-entered exchange rate.Holiday Budget CalculatorBreak a holiday budget into per person per day and leftover.Luggage Weight CalculatorSum packed item weights against an airline limit.Travel Time CalculatorSolve travel time or speed from distance.Trip Cost Split CalculatorSplit holiday or group-trip costs evenly between travellers.
Photography
Crop Factor CalculatorConvert focal length between full-frame and crop-sensor equivalent.Depth of Field CalculatorCalculate near and far depth of field from lens, aperture and focus distance.Flash Exposure CalculatorEstimate flash aperture from guide number, distance and ISO.Hyperfocal Distance CalculatorCalculate hyperfocal distance for landscape focus.Shutter Speed CalculatorSuggest a starting shutter from focal length, or compare exposure stops.
Time & General
Add Time CalculatorAdd hours and minutes to a start time.Age in Days CalculatorCalculate age in days between two dates.Arrival Time CalculatorAdd a duration to a start time to find arrival time.Business Days CalculatorCount weekdays between dates or add business days to a start date.Date Minus Days CalculatorSubtract days from a calendar date.Date Plus Days CalculatorAdd days to a calendar date.Decimal Hours ConverterConvert between hours:minutes and decimal hours for timesheets.Pace CalculatorConvert between running or walking pace and speed.Speed Distance Time CalculatorSolve for speed, distance or time when you know the other two.Time Duration CalculatorFind the duration between two clock times, including overnight.Time Zone Overlap CalculatorFind overlapping working hours between two UTC offsets.What Time Was X Hours AgoFind the clock time a given number of hours before a start time.
Reverse Calculators
Percentage Change CalculatorCalculate percentage increase or decrease between two values.Percentage Difference CalculatorFind percentage difference and percentage change between two values.Reverse Markup CalculatorFind cost from a selling price and markup percentage.Reverse Percentage CalculatorFind the original value from a percentage result.Reverse ROAS CalculatorFind the revenue needed for a target ROAS and ad spend.Reverse Salary CalculatorEstimate gross salary from a target take-home amount.Reverse VAT CalculatorFind the net price and VAT from a VAT-inclusive total.What Percentage Is X of YCalculate what percentage one number is of another.