Employee Expenses
Cashback vs Interest Calculator
Shows how quickly interest costs overtake cashback when a balance is not cleared in full.
Takes about 2 minutes. Your answers stay in your browser, and no email address is required to see your result.
Enter the APR and reward rate shown for your own card. These figures vary by provider and account. The calculator uses your inputs and does not assume a particular partner product.
Does the cashback beat the interest?
Cashback is ahead by £65 over a year
Only true if you keep clearing the rest of the balance in full.
| Cashback earned in a year | £240 |
|---|---|
| Interest paid in a year£1,000 carried for 6 months at 35% APR | £175 |
| Net position | £65 |
| Balance-carrying tipping pointHow long you can carry this balance before interest wipes out the cashback | 8.2 months |
Rewards are not a reason to borrow. If cash is tight, free debt advice is available from Business Debtline.
Assumptions and limitations
- Interest is modelled as simple monthly interest on a flat carried balance: balance × (APR ÷ 12) × months. Real cards compound and may charge from the transaction date.
- Cashback is modelled as a flat percentage of spend with no caps, tiers or point-value conversion.
- Fees, foreign-transaction charges, late-payment charges and annual fees are excluded.
- Enter the APR and reward rate shown for your own card. These figures vary by provider and account. The calculator uses your inputs and does not assume a particular partner product.
- Financial information on this site is general information, not regulated financial advice. We are not authorised to advise you on borrowing, banking or investments. Figures are illustrative and depend on your own circumstances.
Methodology and calculation
This tool is designed with transparency in mind. The results are calculated based on the following logic:
- Compares annual cashback earned against interest accrued on a revolving balance.
Limitations and scope
- Enter the APR and reward rate shown for your own card. These figures vary by provider and account. The calculator uses your inputs and does not assume a particular partner product.