Understand interest costs before choosing a loan. Test extra payments to reduce total cost. Make smarter payoffs with clearer monthly decisions.
Sample scenarios to understand how interest changes with rate, term, and extra payments.
| Scenario | Principal | APR | Term | Frequency | Extra / Period | Expected Effect |
|---|---|---|---|---|---|---|
| Baseline mortgage | ₨ 250,000 | 7.50% | 30y | Monthly | ₨ 0 | Standard payoff, higher lifetime interest |
| Extra payment strategy | ₨ 250,000 | 7.50% | 30y | Monthly | ₨ 200 | Faster payoff, lower total interest |
| Shorter term | ₨ 250,000 | 7.50% | 15y | Monthly | ₨ 0 | Higher payment, much less interest |
| Biweekly cadence | ₨ 250,000 | 7.50% | 30y | Biweekly | ₨ 0 | Small interest reduction from timing |
This calculator uses the standard amortizing payment equation for a fixed-rate loan. It converts APR to a periodic rate based on your payment frequency, then applies interest each period.
Total interest equals the sum of each period’s interest charge: Balance × periodic rate. With a 7.50% APR on monthly payments, the periodic rate is 0.625%. On a ₨250,000 opening balance, first‑period interest is about ₨1,562.50 before principal is applied. As the balance declines, the same rate produces smaller interest charges, which is why early principal reduction matters most.
Frequency changes both the period count and the per‑period rate. Biweekly uses 26 periods per year (rate ≈ 0.2885% per period) and weekly uses 52 (rate ≈ 0.1442%). More frequent payments reduce the balance sooner, so interest is computed on a lower average balance. Over long terms, that timing difference can translate into meaningful cumulative savings.
Extra payments are added after interest and applied to principal. Adding ₨200 per month to a long loan can remove dozens of payments, because each extra unit reduces future interest charges and speeds payoff. A useful metric is interest saved per extra currency unit: the earlier the extra payment is made, the higher the savings multiplier tends to be.
Custom base payments are helpful for “what if” budgeting. To amortize, your effective payment (base plus extra) must exceed interest for that period. At 7.50% APR monthly on ₨250,000, interest starts near ₨1,562.50, so a payment below that level will not reduce the balance and the schedule would never converge. The calculator flags this case immediately.
Use “Total paid” to compare financing options and “Total interest” to isolate borrowing cost. Watch when the interest portion drops below the principal portion; that crossover often signals accelerating payoff. Use the schedule table and graph to spot plateaus caused by small payments, and to verify that extra payments shorten the payoff date. Always remember lender rounding, fees, and day‑count conventions can shift results slightly. Run multiple scenarios to choose the best fit.
It is the sum of all interest charges across the schedule. Each period’s interest is based on the outstanding balance and the periodic rate derived from APR and payment frequency.
Extras go to principal after interest, lowering the balance earlier. A smaller balance generates less interest in future periods, and payoff happens sooner, reducing the number of interest calculations.
Yes, as an estimate. Add financed fees to principal, or compare scenarios with and without them. If fees are paid upfront, they are not reflected in the loan balance or interest schedule.
This tool uses periodic compounding based on your chosen frequency. Daily accrual and different day‑count rules can shift totals slightly, especially with irregular payment dates.
If your custom payment does not exceed the period’s interest, the balance will not fall. In that case, the loan would never amortize, so the schedule can’t reach payoff.
Run both options with the same principal and frequency, then compare total interest, total paid, and payoff date. Use the schedule and graph to see how quickly principal declines.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.