Formula Guide

ROAS Formula: Revenue ÷ Ad Spend

Align your revenue and ad spend inputs, then calculate ROAS as a multiple or percentage.

ROAS multiple

ROAS multiple = attributed revenue ÷ ad spend

ROAS percentage

ROAS percentage = (attributed revenue ÷ ad spend) × 100

5 min read
Updated July 20, 2026
ROAS Calculator Team

ROAS measures the attributed revenue generated for each unit of ad spend. Read the full ROAS definition.

The ROAS Formula

A 5× ROAS and a 500% ROAS are the same result: each $1 of ad spend generated $5 in attributed revenue.

This does not mean the campaign earned $4 in profit. ROAS measures revenue efficiency, not profit.

This matches Google Ads conversion value per cost and Amazon Ads attributed revenue per ad spend.

Formula relationship: attributed revenue divided by ad spend produces the same ROAS as a multiple or percentage.

Check Your ROAS Inputs Before You Calculate

A useful ROAS needs more than two numbers. Confirm this input contract before you divide:

All six input dimensions must describe the same advertising measurement before calculation.
CheckUse matching inputs
ScopeRevenue and spend belong to the same campaign, account, or comparison unit.
PeriodRevenue and spend cover the same reporting dates.
CurrencyBoth inputs use the same currency before division.
Attributed revenueUse revenue attributed to the selected ads, not unfiltered total site revenue.
Spend scopeUse direct ad spend by default. Label any broader custom cost scope and keep it consistent.
Attribution model and windowUse the same attribution model and conversion window for every result you compare.

If any scope differs, the resulting ROAS values are not directly comparable.

How to Calculate ROAS in 4 Steps

  1. 1

    Set the scope and period

    Choose one campaign or account scope and one reporting period for both inputs.

  2. 2

    Record direct ad spend

    Use the advertising cost for that exact scope and period.

  3. 3

    Record attributed revenue

    Use revenue attributed to the same ads under a stated model and window.

  4. 4

    Divide and express the result

    Divide attributed revenue by ad spend. Report the answer as a multiple, a percentage, or both.

ROAS Formula Example

Direct ad spend
$1,000
Attributed revenue
$5,000

$5,000 ÷ $1,000 = 5× = 500%

Each $1 of ad spend generated $5 in attributed revenue. The result describes revenue efficiency; it does not prove $4 of profit.

Want to check your numbers? Use the ROAS Calculator.

Wrong Example: Mismatched Periods

Do not divide 30-day revenue by 7-day ad spend and use the result for comparison.

The division may be mathematically valid, but the inputs describe different periods. Align both to the same dates first.

How to Interpret Your ROAS

A multiple and a percentage are two ways to report the same result. A 5× ROAS is 500% ROAS; both mean $5 in attributed revenue for every $1 of ad spend.

ROAS measures revenue efficiency. It does not subtract product costs, refunds, fees, overhead, or tax, so it is not profit, ROI, or proof that a campaign is profitable.

Judge the result against the threshold based on your own economics. Calculate your break-even ROAS.

Common ROAS Calculation Mistakes

  1. 1

    Mixing scope, period, or currency

    Revenue and spend must cover the same campaign or account scope, reporting dates, and currency.

  2. 2

    Using total site revenue

    Use revenue attributed to the selected ads, not all revenue the business received during the period.

  3. 3

    Changing the cost or attribution basis

    Do not compare results after changing the included costs, attribution model, or conversion window without clearly relabeling the metric.

  4. 4

    Treating ROAS as profit or ROI

    ROAS is a revenue-to-ad-spend ratio. It does not include every cost needed to calculate profit or ROI.

When the Basic ROAS Formula Is Not Enough

Keep the basic formula for realized attributed revenue and direct ad spend. Use a clearly labeled advanced basis when the decision requires a different question:

Refunds and net revenue

Gross revenue ignores refunds. If you use net revenue, deduct refunds consistently and label the result as net-revenue ROAS.

Attribution windows

A longer window can credit more conversions. Results from different windows or models are not directly comparable.

Forecast LTV and pipeline value

Forecast customer lifetime value and B2B pipeline value are estimates, not realized revenue. Label forecast-LTV or pipeline-value ROAS explicitly.

Profit, incremental, and marginal views

Profit-aware, incremental, and marginal measures answer different questions about costs, causal lift, or the next unit of spend. Name the basis instead of presenting it as basic ROAS.

Google Ads notes that changing an attribution model changes how conversion credit is assigned and can change reported performance. Review the Google Ads attribution model guidance.

ROAS Formula FAQ

How do I calculate ROAS in Excel or Google Sheets?

If attributed revenue is in B2 and ad spend is in C2, enter =B2/C2 for the multiple or =(B2/C2)*100 for the percentage. Format the inputs in the same currency and keep their scope and dates aligned.

Can ROAS be zero or below 1×?

Yes. Zero means the selected ads have no attributed revenue. A result below 1× means attributed revenue is lower than ad spend; it does not by itself show the final profit or loss.

Should agency, creative, or platform fees count as ad spend?

Basic ROAS normally uses direct media spend. You may include agency, creative, or platform fees for a broader custom cost view, but label that basis and use it consistently instead of comparing it with platform ROAS.

Why does platform-reported ROAS differ from my calculation?

Platforms can use different attribution models, conversion windows, time zones, currencies, and conversion values. Compare the same settings and source data before treating the figures as equivalent.

Sources and Methodology

This guide uses the standard attributed-revenue-to-ad-spend definition, then separates input consistency and advanced measurement choices from the basic formula. Platform definitions support the formula and attribution boundaries; they are not universal profitability standards.

Reviewed July 20, 2026 by the ROAS Calculator Team.