Calculator Inputs
Formula Used
Purchase charge = previous purchase balance × purchase APR ÷ interest basis × billing cycle days.
Cash charge = previous cash advance balance × cash APR ÷ interest basis × billing cycle days.
Total finance charge = purchase charge + cash charge + fixed account fees.
Estimated statement balance = previous balances + new purchases - payments - credits + total finance charge.
In the previous balance method, current payments and purchases do not change the interest base for that same cycle.
How To Use This Calculator
Enter the balance from the prior statement. Add separate cash advance balance when needed. Type the APR values, billing days, and interest basis. Add payments, credits, new purchases, and fixed fees. Press calculate. Use the export buttons to save the same scenario as a CSV file or a simple PDF file.
Example Data Table
| Case | Previous Purchase Balance | Purchase APR | Cash Balance | Cash APR | Days | Payments | New Purchases | Fixed Fees |
|---|---|---|---|---|---|---|---|---|
| Standard card | $1,200.00 | 19.99% | $0.00 | 29.99% | 30 | $150.00 | $200.00 | $0.00 |
| Cash advance | $950.00 | 18.50% | $300.00 | 27.75% | 31 | $100.00 | $80.00 | $10.00 |
| High payment | $2,400.00 | 22.99% | $0.00 | 29.99% | 28 | $900.00 | $120.00 | $0.00 |
Previous Balance Method Guide
What This Calculator Does
The previous balance method charges interest on the balance from the last statement. It does not reduce the finance charge when you make payments during the current cycle. It also does not add current purchases to the interest base. That makes the method simple, but sometimes costly for users who pay after the new period begins.
Why The Method Matters
Credit cards and store accounts may use different finance charge methods. The previous balance method is easy to audit because the starting balance is known. You can test the periodic rate, cycle length, extra fees, and cash advance balances. The calculator separates purchase balance and cash balance. This helps when each balance has a different annual rate.
Interpreting The Results
The main finance charge is calculated from the previous balance only. Payments, credits, and new purchases are then used to estimate the ending statement balance. This layout shows why the finance charge may stay high even after a payment. It also shows the average daily cost and the estimated minimum payment.
Planning With The Calculator
Use the tool before a statement closes. Enter the balance from the previous bill. Add the annual rate and the exact billing days. Include any cash advance balance if it has a separate rate. Add account fees only when they apply. Compare results under 365 day and 360 day bases. Small changes can matter across many months.
Good Use Cases
This calculator is useful for credit card reviews, personal budgets, loan style billing, retail cards, and finance education. It can help explain statement charges to clients or students. It can also support spreadsheet checks, audit notes, and payment planning. Export the result when you need a record.
Important Limits
This tool is an estimator. Your issuer may use rounding rules, grace periods, compounding, penalty rates, or separate promotional balances. Statement disclosures control the final charge. Always compare the result with your actual agreement and billing statement.
Record Keeping Tip
Save a copy after each scenario. Name exports with the cycle month and rate used. This practice makes comparisons clearer. It also helps you notice fee changes, unusual balances, or billing days that do not match your expectations. Review every statement carefully.
FAQs
What is the previous balance method?
It is a finance charge method based on the balance from the prior statement. Current cycle payments usually do not reduce the balance used for that cycle's interest calculation.
Does a payment lower the finance charge here?
No. Under this method, the finance charge is based on the previous balance. The payment lowers the estimated statement balance, but not the interest base for the current cycle.
Are new purchases included in the interest base?
No. New purchases are added after the finance charge is calculated. They affect the estimated statement balance, not the previous balance interest calculation.
Why are there two APR fields?
Some accounts charge cash advances at a different rate. Separate fields help estimate purchase interest and cash advance interest more clearly.
What is the interest basis?
The basis converts an annual rate into a daily rate. Many estimates use 365 days. Some agreements or business models may use 360 days.
Can I include account fees?
Yes. Enter fixed fees in the account fee field. The calculator adds them to the total finance charge and estimated statement balance.
Is the result exact for my card?
It is an estimate. Your issuer may apply grace periods, rounding, compounding, penalty rates, or promotional balances. Always compare with your card agreement.
What can I export?
You can download a CSV file for spreadsheets. You can also download a simple PDF summary for records, reviews, and client notes.