How Home Loan Prepayment Savings Are Calculated
Home-loan interest is commonly calculated on the outstanding principal. An extra payment reduces that balance, so less interest may accrue in later months. This calculator creates the original monthly repayment schedule and a second schedule with your selected prepayments, then compares interest, EMI, tenure, and total payments.
Monthly interest estimate
Opening Balance × Annual Rate ÷ 12
Principal in an EMI
Scheduled EMI − Monthly Interest
The model assumes a fixed annual rate, monthly reducing balance, and a prepayment applied after the scheduled EMI in the selected month. It excludes future rate changes, daily-interest timing, taxes, insurance, and lender-specific rounding unless you represent a known cost in the optional charges field.
Reduce EMI or Reduce Tenure?
Reduce loan tenure
The regular EMI remains broadly unchanged and the principal falls faster. This commonly produces the larger interest saving and an earlier payoff, but preserves the existing monthly commitment.
Reduce monthly EMI
After a prepayment, the calculator recalculates EMI over the remaining original period. This can free monthly cash flow, though the interest saving may be lower than keeping EMI unchanged.
The right choice is personal. Consider job and income stability, emergency reserves, upcoming expenses, other higher-interest debts, retirement goals, and whether the lender permits the requested option. The two scenario cards let you compare both outcomes using identical prepayment amounts and timing.
One-Time and Recurring Prepayment Planning
A lump-sum payment can model a bonus, asset sale, maturity proceeds, or accumulated savings. Recurring extra payments can model a monthly EMI top-up, quarterly surplus, or annual bonus. Earlier payments often have more time to reduce future interest, but every prepayment should be considered alongside liquidity and other financial priorities.
- Use the current outstanding principal—not the original sanctioned amount
- Enter the rate and remaining tenure from the latest loan statement
- Model known charges so gross and net savings are not confused
- Compare both strategies before asking the lender to revise the schedule
- Keep a suitable emergency fund instead of using all available cash
- Download the monthly schedule and compare it with the lender's quotation
What to Confirm With Your Lender
Check the minimum part-payment amount, frequency limits, lock-in period, eligible payment channels, processing time, prepayment charges, and whether the lender automatically reduces EMI or tenure. Ask for written confirmation and an updated amortization schedule after the payment is credited.
Prepayment is not automatically the best use of cash
Compare the effective loan cost, tax treatment where applicable, investment risk and return, inflation, emergency liquidity, and other debts. A guaranteed reduction in loan interest and a market investment do not have the same risk profile.
Important: Planning Estimate Only
This tool provides an educational estimate, not financial, tax, legal, or lending advice. Actual savings and revised payments depend on lender calculations, payment dates, rate changes, account terms, fees, taxes, and rounding. Verify the exact effect and any charge with your lender before paying.