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Contribution Margin Calculator

Revenue is vanity. Contribution margin is reality. See your true profit after COGS, shipping, returns, payment fees and ad spend — and whether your ads are actually working.

Revenue & Costs

Total sales revenue for the period (before any deductions).

$

Total product cost for the period — what you paid suppliers for inventory sold.

$

Total cost you paid to ship and fulfil orders for the period.

$

Total value of returned or refunded orders for the period.

$

Total fees charged by your payment gateway (Shopify Payments, Stripe, etc.).

$

What you spent on Google Ads, Meta, or any paid channel for the period.

$
Contribution Margin
—
True profit after all variable costs including ad spend.
CM %
—
ROAS (True)
—
Gross Profit
—
Revenue minus COGS only.
Gross Margin %
—
Before shipping, fees, returns & ads.
True CPA
—
Ad spend ÷ contribution margin generated.
Total Deductions
—
COGS + shipping + returns + fees + ads.

Step-by-Step Breakdown

1
Gross Profit
Revenue − COGS
2
After Shipping & Fulfilment
Gross Profit − Shipping
3
After Returns & Refunds
Previous − Returns
4
After Payment Fees
Previous − Payment Fees
5
Contribution Margin (after Ad Spend)
Previous − Ad Spend

Where to Find Your Numbers

All these figures come from reports you already have — here's exactly where to pull them.

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Revenue, COGS & Shipping

Core financials from Shopify

  • 1In Shopify → Analytics → Finances → Summary. Revenue, COGS, and shipping costs are broken out by date range.
  • 2For COGS: Shopify → Finances → Cost of goods. Make sure products have cost prices entered for accuracy.
  • 3Carrier invoices (Australia Post, Sendle) give you the actual shipping paid — reconcile against Shopify's figure monthly.
Tip: Set a consistent date range (e.g. last full month) and pull all figures from the same period for an accurate picture.
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Returns & Payment Fees

The costs most stores forget

  • 1Returns: Shopify → Analytics → Finances → Returns. Total refunded value for the period.
  • 2Payment fees: Shopify → Analytics → Finances → Payments. "Total transaction fees" column shows gateway charges.
  • 3Stripe or Afterpay users: check your gateway dashboard → Reports → Fees for the period.
Tip: Payment fees and returns are easy to overlook. Combined, they can reduce your contribution margin by 3–8 percentage points.
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Ad Spend

Total across all paid channels

  • 1Google Ads: Campaigns → select your date range → look at "Cost" column at account level.
  • 2Meta / Facebook Ads: Ads Manager → set date range → "Amount spent" at account level.
  • 3If running multiple channels, add them together — contribution margin is a whole-of-business metric.
Tip: Use the same date range as your revenue and cost figures. Mismatched periods will skew the result significantly.