Estimate the reward on eligible spending, apply an optional reward cap, and see how a fixed fee affects the net benefit. Use the result to compare the same purchase under different cash-back offers.
How to use this calculator
Enter the purchase amount that qualifies for rewards and the cash-back percentage. If the offer caps the reward in money, enter that maximum. Leave it blank for uncapped rewards. Add a fixed fee under the optional fields when it belongs in your comparison.
A reward cap is different from a spending cap. If 5% cash back applies only to the first 500 of spending, the maximum reward for that portion is 25. This calculator models one rate and one reward cap; calculate different tiers separately.
Understanding the result
Cash back is the reward after the cap. The effective reward rate is cash back divided by the entered spending, so a cap can make it lower than the advertised rate. Net reward subtracts the optional fee. Net cost adds that fee to spending, then subtracts cash back. Rewards may arrive later, so net cost is not necessarily today's card charge.
Examples
A capped 3% offer
A 1,200 purchase at 3% would earn 36. With a reward cap of 25, cash back is 25 and the effective rate is about 2.0833%. With no fee, net cost is 1,175.
A fee larger than the reward
If the same purchase earns 25 but carries a 40 fee, net reward is −15 and net cost is 1,215. The offer adds cost under those assumptions.
Formula
Uncapped reward = eligible spending × rate / 100
Cash back = smaller of uncapped reward and reward cap
Net reward = cash back − fee
Net cost = eligible spending + fee − cash back
With zero spending the effective reward rate displays as zero rather than dividing by zero.
Check the offer terms
Use eligible spending after any exclusions or adjustments required by the offer. Returns, merchant categories, activation requirements, minimum redemption amounts, annual limits, and promotional dates can change what is paid. If a cap applies across a billing period, enter the remaining cap available for the purchase you are evaluating.