RefundMath

Stop over-refunding discounted orders.

When Shopify doesn’t redistribute discount codes on partial returns, you can refund too much. RefundMath calculates the exact amount using the order’s original discount allocations.

Install on Shopify See example

Free plan includes 5 calculations. Pro is $9/mo with a 14-day trial.

Example calculation

Order #1042 · 10% off code SAVE10

Item returned$50.00

Discount credit (allocated)−$5.00

Tax credit$3.60

Shopify may suggest$50.00

Correct refund

$48.60

Saved $1.40 on one return — compounds across every discounted refund

How merchants use it

Install from the App Store, open RefundMath in admin, paste an order ID or URL, select items to return, then copy the correct refund amount into Shopify’s refund screen.

1. Load the orderPaste the Shopify order URL or numeric ID.

2. Select returnsChoose line items and quantities with live estimates.

3. Copy & refundUse the exact amount — including discount and tax credit.

Simple pricing

One avoided over-refund can pay for months of Pro. Start free on real orders.

Free

5 calculations — no credit card

Pro

$9/mo

Unlimited calculations · 14-day free trial · Cancel anytime