Reverse Calculators
Reverse ROAS Calculator
Enter ad spend and target ROAS to see the revenue you must generate.
Revenue for a ROAS target
Marketers often start from a target ROAS and need the revenue (or spend) that makes the ratio true. Reverse ROAS answers ‘at this ROAS, what revenue does £X of spend imply?’ or the spend allowed for a revenue goal. It does not by itself say whether that ROAS is profitable — thin margins need higher ROAS to break even. Pair the result with break-even ROAS and cash left after ads on ad spend profit. Contribution margin from gross margin tells you whether the reversed revenue is worth chasing. Attribution quirks still apply: platform ROAS is not finance revenue. New customer and retention campaigns rarely share the same true incrementality, so reverse them as separate scenarios when you can. Planning model only — not media-buying advice. Use separate reverses for prospecting and remarketing if their returns differ, rather than one blended vanity target that flatters the weekly dashboard.
Worked example
At a 4.0 ROAS, £2,500 of spend implies 4.0 × £2,500 = £10,000 attributed revenue. If you need £12,000 revenue at the same ROAS, allowed spend is 12,000 ÷ 4 = £3,000. If break-even ROAS is 5.0 because margin is 20%, a 4.0 target still loses money even when the reverse maths is tidy.
Limits and assumptions
Ignores incrementality, delayed conversions and stock caps. ROAS definitions differ between platforms and finance. Not a budget recommendation on its own.
Frequently asked questions
How do I get revenue from spend and ROAS?
Revenue = ROAS × spend when ROAS is expressed as a multiple (e.g. 4.0).
How do I get spend from a revenue target?
Spend = revenue ÷ ROAS.
Is high ROAS always good?
No — compare with break-even ROAS for your margin.
Should I use decimal or percentage ROAS?
Be consistent. 400% is the same idea as 4.0×; do not mix them in one formula.
Can I reverse MER instead?
Same algebra if MER is revenue ÷ ad spend; still check profit separately.