Net profit ratio sounds like a synonym for net profit margin, and in most contexts the two are used interchangeably. The technical distinction: net profit ratio divides by net revenue (after refunds and discounts), while net profit margin most commonly divides by gross revenue. For subscription businesses with a lot of promo activity or refunds, the choice of denominator matters.
The formula
Net Profit Ratio = Net Profit ÷ Net Revenue
Expressed as a decimal (0.15) or a percentage (15%). Net revenue here means gross revenue minus refunds, returns, and discounts. Some accounting frameworks include sales tax in the deduction; most subscription businesses treat tax as a pass-through and exclude it from both numerator and denominator.
When the ratio differs from the margin
A subscription business with heavy first-order discounting will see a meaningful gap between net profit margin (vs. gross revenue) and net profit ratio (vs. net revenue). The ratio is the more honest representation of how much of the revenue you actually keep is converted to profit — because it strips out the discounts and refunds that never really represented sustainable revenue in the first place.
How subscription operators use it
- Internal trend analysis. Same denominator definition every period; watch for direction.
- Channel comparison. Customers from discount-heavy channels will look much worse on net profit ratio than on net profit margin — and the ratio is the truer view.
- Investor communication. Some investors specifically ask for the net-revenue-based ratio because it neutralizes accounting policy differences.
The bigger picture
For most subscription merchants on Shopify, the distinction between margin and ratio is academic — the numbers come out close enough that picking one and being consistent is more important than choosing the "right" one. State which definition you are using, apply it consistently, and focus operational energy on improving the underlying drivers (CAC, COGS, churn) rather than on reconfiguring the formula.