Mammoth Agency

Free tool

POAS calculator

ROAS counts revenue. It ignores your margin. Drop in your numbers to see your real profit on ad spend - the figure your P&L actually feels.

Your costs (% of revenue)

Contribution margin: 46%

Profit on ad spend (POAS)

1.84×

Profitable spend

Profit per £1 spent
£0.84
ROAS
4.00×
Break-even ROAS
2.17×
Profit after ad spend
£8,400
Get a free profit & competitor review

How the POAS calculation works

POAS = (revenue − COGS − shipping − returns) ÷ ad spend. It strips your costs out of revenue to leave contribution margin, then measures how much of that profit each pound of ad spend returns. A glossy ROAS can hide a thin margin; POAS surfaces it. The calculator also shows your break-even ROAS - the point below which ads lose money.

Frequently asked questions

What is POAS?

POAS (Profit on Ad Spend) is your contribution margin - revenue after COGS, shipping and returns - divided by ad spend. Where ROAS measures revenue per pound of spend, POAS measures the profit you actually keep. A POAS above 1.0 means each pound of ad spend returns more than a pound of profit.

How do you calculate POAS?

POAS = (revenue − COGS − shipping − returns) ÷ ad spend. For example, £40,000 revenue at a 46% contribution margin is £18,400 of profit; on £10,000 ad spend that is a POAS of 1.84× - so each £1 of spend returns £0.84 of profit, even though the ROAS is 4.0×.

What is a good POAS?

A POAS above 1.0 is profitable; below 1.0 you lose money on ads. Most well-run ecommerce accounts target somewhere in the 1.3×-2.0×+ range depending on margin and growth goals. The right number depends on your contribution margin - use the break-even ROAS this tool shows to find your floor.

POAS vs ROAS - what is the difference?

ROAS counts revenue and ignores your margin, so a high ROAS can still be a loss. POAS counts profit. A 5× ROAS on a 20% margin product barely breaks even, while a 3× ROAS on a 60% margin product genuinely makes money. POAS tells you which.

Profit is only half the picture - your stock position is the other half. See inventory-aware advertising for when to scale, ease or clear a product based on profit and days of cover, or check the glossary for every metric explained.