How much cashback will you get on your next order? You can find out with one small sum. Multiply the price by the cashback rate. If you spend $85 and the rate is 3%, you get $85 × 0.03 = $2.55 back. A cashback calculator does this for you, and it helps to know the steps so you can see what the answer means.
The simple formula
The rule has two parts.
Turn the percentage into a decimal. Move the decimal point two places to the left. So 3% becomes 0.03, 5% becomes 0.05, and 1.5% becomes 0.015.
Multiply the decimal by the amount you spend.
Cashback = amount spent × rate as a decimal.
Example 1: one purchase, one rate
You buy a jacket for $120 and the rate is 5%. Change 5% to 0.05. Then 120 × 0.05 = $6. You get $6 back, so the jacket costs you $114 in the end.
Here is a quick shortcut. To find 10%, move the decimal point one place to the left. To find 5%, find 10% and cut it in half. For $120, 10% is $12, and half of that is $6.
Example 2: some of the order does not count
Many offers do not pay cashback on everything in the basket. Say you spend $250. Only $200 of it is eligible for a 5% rate, and the other $50 is not.
Eligible amount: $200
Cashback: 200 × 0.05 = $10
Real rate on the full order: 10 ÷ 250 = 0.04, or 4%
Final cost: 250 − 10 = $240
The offer says 5%, but you really get 4% of the whole order. Always check which part of your basket counts.
Example 3: different rates in one shop
Some cards pay different rates on different things. Suppose you spend $60 on groceries at 3% and $40 on fuel at 2%.
Groceries: 60 × 0.03 = $1.80
Fuel: 40 × 0.02 = $0.80
Total cashback: $2.60 on $100, which is 2.6%
Work out each part on its own, then add the answers. These rates are only examples, so use the real rates from your own offer.
Check your monthly total
One order tells you little. A month of orders tells you more. Say you got $12.40, $9.60 and $14.00 in cashback over three months. The total is $36.00. To find your typical month, use an average calculator and divide by 3, which gives $12.00 a month.
That number helps when you plan your budget. It is better to plan with the average than with your best month.
Does tax count?
It depends on the offer. Say you buy something for $100 and there is $8 of sales tax. If cashback is paid on the price before tax, 5% of $100 is $5. If it is paid on the total, 5% of $108 is $5.40.
The difference is small here, but it grows with big purchases. The terms will say which one applies. If they do not, assume the smaller amount.
Watch the rounding
Cashback often ends up with part of a cent, and companies round it in their own way. Some round up, some round down, and some add up the exact amounts first. A tiny difference of one cent is normal, so do not worry if your answer is slightly different from what you receive. Your own check is still worth doing, because it shows you the rough amount to expect.
Working backwards
Sometimes you know the cashback and want to find what you spent. Say you got $4.50 back at a rate of 3%. Divide the cashback by the rate: 4.50 ÷ 0.03 = $150. This is handy when you want to check that a payment matches the order you remember. If the numbers do not match, the offer may have counted only part of the order.
When will the money arrive?
Working out the amount is half the job. The other half is the date. Some offers pay after a set number of days, and many say the money is "pending" until then. If you buy on 3 March and the offer says it pays after 30 days, you should expect it around 2 April.
When the date is close, it helps to calculate days from your purchase date, so you know when to check your account. If nothing has arrived a few days after the date, contact the company with your order number.
Quick mistakes to avoid
Using 5 instead of 0.05 in the sum. That would give you 100 times too much.
Forgetting that some items may not count.
Mixing up the rate on the offer and the rate you really get.
Counting the cashback before it is confirmed.
Final thoughts
Cashback sums are easy once you know the pattern: change the percentage to a decimal and multiply. Check which part of your order counts, add up different rates one by one, and keep the dates in mind. Then you always know what you are really paying.
