Cash Back Calculator
Add up monthly and yearly cash back across spending categories with different reward rates.
How it works
Cash back = Σ (category spend × category rate) · Yearly = monthly × 12
Cash back is simply each category’s spending times its reward rate, summed up. The effective rate — total cash back divided by total spend — shows your real blended reward, which is usually well below the headline bonus rate because most spending falls in lower-rate categories.
Worked example
$600 groceries at 3%, $200 gas at 2% and $800 on everything else at 1% earn $18 + $4 + $8 = $30 a month, or $360 a year — an effective 1.88% on $1,600 of spending.
Frequently asked questions
Is a high-rate bonus category worth it?
Only if you spend enough there to beat a flat-rate card. Do the math on your actual spending — a 5% category on $100 a month earns less than a flat 2% on $600.
Does an annual fee change the picture?
Yes. Subtract the fee from your yearly cash back to find the net reward. A fee card wins only if the extra rewards clear the fee comfortably.
Does carrying a balance cancel out rewards?
Almost always. Card interest (often 20%+ APR) dwarfs 1–5% rewards. Cash back only pays off if you clear the statement in full each month.
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This is an educational estimate, not financial advice. Confirm figures with your lender, advisor or tax professional.