Cashback on one item is easy. Cashback on a basket of many items is where people get lost, because some items earn more, some earn less and some earn nothing. The offer’s dates matter too. A days calculator can show how many days an offer has left, and this guide shows you how to work out the cashback itself, line by line.
All the rates below are examples. Your own offer may count things in a different way, so always read its terms.
The basic rule
Work out each item on its own, then add the results. For each item, multiply the price by its cashback rate. Items that do not qualify get zero.
Cashback for the order = the sum of (price × rate) for each qualifying item.
Example 1: one rate, some items left out
You order five things online.
| Item | Price | Counts? |
| Shirt | $40 | Yes |
| Shoes | $90 | Yes |
| Phone case | $20 | No |
| Gift card | $50 | No |
| Delivery | $8 | No |
The offer pays 5%, but only on the shirt and the shoes. Add the eligible prices: 40 + 90 = $130. Then 130 × 0.05 = $6.50.
You paid $208 in total, so your real rate is 6.50 ÷ 208 = 3.125%, or about 3.13%. The offer says 5%, but you really get a little over 3%.
Example 2: different rates in one basket
Now take a basket where each item has its own rate.
- Item A: $50 at 4% = $2.00
- Item B: $30 at 2% = $0.60
- Item C: $40 at 1% = $0.40
The total price is $120 and the total cashback is $3.00. The real rate is 3.00 ÷ 120 = 2.5%.
Do not average the rates
It is tempting to add 4, 2 and 1, and then divide by 3. If you calculate average rates that way, you get 2.33%. But the real rate is 2.5%, because the biggest item has the highest rate. When the items are different sizes, always work from the money, not from the percentages. The rule is simple: add all the cashback, then divide by all the spending.
What happens if you return one item?
Say you send back the shirt in Example 1. The eligible total drops from $130 to $90, so the cashback becomes 90 × 0.05 = $4.50. You lose $2.00, which is 5% of the $40 shirt.
Many offers work this way, but some take back all the cashback on the whole order. The terms of your offer will tell you.
What if there is a coupon?
A coupon changes the price you pay. Some offers pay cashback on the price before the coupon, and others on the price after. Say shoes cost $90, and you use a $10 coupon.
- Cashback before coupon at 5%: $90 × 0.05 = $4.50
- Cashback after coupon at 5%: $80 × 0.05 = $4.00
The gap is only $0.50 here, but it grows with big orders. If the terms do not say, assume the smaller amount.
Plan with your real rate
After a few orders, you will know the real rate you usually get. If it is around 3%, plan with 3%, not with the 5% in the advert. Your plan then matches what really arrives, and any extra feels like a bonus.
Tax and delivery
Tax and delivery fees often do not count. Some offers include tax, and others leave it out. Delivery is usually left out. If you are not sure, work out two figures: one with these costs and one without. Plan with the smaller one.
Rounding
Cashback is often rounded to the nearest cent after each item or after the whole order. This can change the total by a cent or two. Do not worry if your answer is slightly different from what you receive.
A checklist before you pay
- List every item and its price.
- Mark which items qualify.
- Find the rate for each qualifying item.
- Multiply and add.
- Divide by the total paid to see your real rate.
- Note the date when the cashback should arrive.
Common mistakes
- Using the offer’s headline rate on the whole basket.
- Adding gift cards or delivery to the eligible amount.
- Averaging the rates instead of adding the money.
- Forgetting that returns may cut the cashback.
- Expecting the cashback to arrive straight away.
Check each line
When the order is large, mistakes are easy. Go back over each line with a cashback calculator and compare your total with the one you expect to see. If your result and the offer’s result differ by more than a few cents, look for an item that did not count. Keep your receipt until the money arrives.
Final thoughts
To find the cashback on a mixed basket, work out each item, add the results and divide by what you paid. Leave out items that do not qualify, and check the rules for coupons, tax and returns. The headline rate is only a guide, and the real number comes from the money.