How to Calculate ROAS: Formula, Steps, and Break-Even (2026)

How to calculate ROAS (the formula)

ROAS = attributed ad revenue ÷ ad spend.

That is the whole calculation. If a campaign spent $1,200 and you attribute $4,800 of purchase revenue to it, ROAS is 4,800 / 1,200 = 4.0x (or 400%). Teams report either the multiplier or the percentage—pick one format and keep it consistent across dashboards.

• Revenue (numerator): conversion value you credit to the ads in the window you care about (same-day purchases, D7 value, subscription first payment, etc.).
• Spend (denominator): media cost for the same window. Match finance rules on whether VAT, platform fees, or agency markup sit inside “spend.”

ROAS answers efficiency of attributed revenue per media dollar. It is not full profit. For profit you still need contribution margin, refunds, and non-media costs—see ROI vs ROAS below.

Step-by-step: calculate ROAS in a spreadsheet

1. Export platform spend for the date range (campaign or ad-set grain).
2. Export attributed revenue for the same range and grain (platform, MMP, or warehouse).
3. Align rows on campaign/ad-set IDs.
4. Compute ROAS = revenue / spend per row; also compute a blended total: sum(revenue) / sum(spend).
5. Flag rows with spend but zero revenue (tracking breaks or dead creatives).
6. Optionally add break_even_roas = 1 / contribution_margin and mark rows below break-even.

Worked example

If contribution margin after COGS and fees is 40%, break-even ROAS ≈ 1 / 0.40 = 2.5x. Prospecting A sits on the line; remarketing and the blend clear it.

Platform views: where the numbers come from

• Meta Ads Manager: use Purchase conversion value (or your custom value event) ÷ Amount spent for the selected attribution setting.
• Google Ads: conversion value ÷ cost; if you use tROAS bidding, the reported ROAS still depends on which conversions you included in the goal.
• TikTok / other: same pattern—value events ÷ cost for a fixed window.

Always note the attribution window (1-day click, 7-day click, 1-day view, etc.). Changing the window changes ROAS without changing the business.

For bid-strategy context when you move from reporting to automation, see Target CPA vs Target ROAS. For the plain definition and benchmarks, see What Is ROAS in Advertising?.

Break-even ROAS and when “good” is good enough

Break-even ROAS ≈ 1 / contribution_margin

Contribution margin here means revenue left after variable product cost, shipping, and payment fees—before salaries and tools. If margin is 25%, you need about 4.0x ROAS just to break even on contribution. A “4x target” copied from a SaaS blog can be suicidal for thin-margin DTC and lazy for high-margin digital goods.

Also separate:

• Platform ROAS — what the ad UI shows under its attribution rules.
• Blended MER — total revenue / total marketing spend, useful when attribution is noisy.
• Incremental ROAS — lift from holdouts or geo tests when budgets are large.

Common calculation mistakes

1. Mismatched windows — spend for 7 days, revenue for 28 days (or the reverse).
2. Gross vs net revenue — ignoring refunds and chargebacks inflates ROAS for weeks.
3. Mixing grains — account-level spend with campaign-level revenue, or including organic orders in the numerator.
4. Comparing platforms raw — Meta, Google, and TikTok credit differently; normalize in one warehouse before ranking channels.
5. Optimizing only remarketing ROAS — high remarketing ROAS can hide weak prospecting; judge cold traffic on its own target and on blended MER.
6. Scaling on 24-hour ROAS alone — short windows punish long consideration and delayed subscriptions; use D7/D30 where LTV matters.

Channel spend controls (limits, prepaid vs postpaid) change how fast you can test these numbers in practice—see Ad Account Spending Limit and Prepaid Ad Account vs Postpaid.

FAQ

Is ROAS a percentage or a multiple?

Either. 4.0x and 400% are the same ratio. Dashboards should pick one label so week-over-week charts stay readable.

Do I include creative production in the denominator?

Classic media ROAS uses media spend only. If finance wants fully loaded cost, label it clearly (e.g. “fully loaded ROAS”) so you do not mix series.

How is ROAS different from ROI?

ROAS = attributed revenue / ad spend. ROI uses profit relative to cost and often folds in non-media costs. Strong ROAS with thin margins can still be weak ROI.

How often should I recalculate ROAS?

Daily for tracking anomalies; weekly for budget shifts; monthly after margin or refund-rate changes reset break-even.

Bottom line

How to calculate ROAS: divide attributed ad revenue by ad spend for a matched window and grain, know your break-even from contribution margin, and do not treat platform ROAS as cash until refunds and blended MER agree. Once the math is clean, use it to choose bids and budgets—not to decorate slides.