ROAS & ad cost share (PNO/ACoS) calculator

How PNO and ROAS are calculated

PNO and ROAS are two sides of the same coin. Both measure whether your ads pay off. PNO is the term Czech marketers use for ad spend as a share of revenue. Internationally you'll see it as ACoS:

ROAS = revenue from ads ÷ ad spend (how many CZK of revenue you get from 1 CZK of ads)
PNO = ad spend ÷ revenue from ads × 100 (what % of revenue your ads eat up)

Neither PNO nor ROAS alone tells you whether you're making money. You only find out by comparing them with your margin. Your break-even PNO equals your margin in percent: with a 35 % margin, you can spend at most 35 % of revenue on ads before you start losing money. The goal is to keep your PNO safely below that number.

FAQ

What is PNO?

PNO (Czech for ad cost share, the same as ACoS) tells you what percentage of revenue your ads eat up. It's ad spend ÷ revenue × 100. The lower, the better.

What is ROAS?

ROAS (return on ad spend) is how much revenue one koruna of ads brings in. A ROAS of 5 means 5 CZK of revenue for every 1 CZK of ads. PNO = 1 ÷ ROAS.

What is a good PNO or ROAS?

Your margin decides. Break-even PNO equals your margin in percent, so a good PNO sits safely below your margin. With a higher margin you can afford a higher PNO.

How do you lower PNO?

Better targeting and creatives, a higher website conversion rate, a higher order value, repeat purchases and cutting campaigns that don't perform. A strong brand helps too, because people buy even without ads.

This calculator treats margin as contribution margin (after cost of goods and variable costs, before ads). Your e-shop's fixed costs aren't included. For those, use the break-even calculator.