Post-ad contribution calculator
Estimate campaign contribution after variable costs and advertising, before fixed overhead and tax.
Last updated
Written by Madly editorial
01 / Your inputs
Run the numbers
Example figures are filled in so you can see a result straight away. Replace them with your own. Results update as you type; no data is sent or saved.
Revenue for the period being evaluated.
Variable costs for the same orders and period.
Advertising cost for the same period.
02 / Calculation
Post-ad contribution
Calculated result
£400.00
Unit: £
Formula
Post-ad contribution (£) = revenue (£) − variable costs (£) − ad spend (£).
How to read this
A negative result means the campaign did not cover the costs entered. Include missing costs before making a decision.
Assumptions
All figures cover the same set of orders and period. This is contribution, not accounting net profit; overhead, tax and refunds not in variable costs are excluded.
How to use this tool
- Enter revenue for the period.
- Add cost of goods, shipping, payment fees and refunds.
- Add the ad spend.
- Read the profit remaining and the margin as a share of revenue.
Worked example
Illustrative example: £2,000 revenue − £800 variable costs − £700 ads leaves £500 contribution.
What this measures
Use this to separate sales volume from the amount left after direct costs and ads.
Formula and units
Post-ad contribution (£) = revenue (£) − variable costs (£) − ad spend (£).
Assumptions and review notes
All figures cover the same set of orders and period. This is contribution, not accounting net profit; overhead, tax and refunds not in variable costs are excluded.
A negative result means the campaign did not cover the costs entered. Include missing costs before making a decision.
Post-ad contribution shows what remains after the entered variable costs and advertising. It is not net profit or proof of incremental advertising impact. A positive figure still has to cover fixed overhead, software and staff. A negative launch-period contribution is a loss to fund explicitly, not a repeat-purchase guarantee.
- Refunds and chargebacks.
- Fixed costs not included here.
- Timing differences between spend and orders.
- Discounts applied to the revenue figure.
- Using revenue before refunds.
- Leaving out fees and shipping.
- Counting only platform-attributed revenue.
- Comparing a short period against a long one.
A closer look
Common questions.
- What costs should I include?
- Product cost, shipping, payment fees, refunds and ad spend at a minimum.
- Is this net profit?
- No. It excludes overheads such as software and salaries, so it is closer to contribution after ads.
- Why compare with ROAS?
- ROAS ignores costs. This figure shows whether revenue left anything after them.
- Which revenue should I enter?
- Store revenue after discounts and refunds is the most reliable.
- Can I use it for one product?
- Yes, as long as you allocate shipping and ad spend to that product fairly.