Extra Payment Calculator
See how much extra payments save on your bond or loan. Calculate interest saved, time saved, and the impact of a once-off lump sum payment.
Quick Calculator Get a fast estimate
R
%
R
Additional amount paid each month on top of your regular repayment.
R
Bonus, inheritance, or windfall applied now.
Interest Saved
R 496 011
Time Saved
4 yr 5 mo
New Payoff Time
15 yr 8 mo
Original Payoff Time
20 years
Regular Monthly Payment
R 13 004
Extra Monthly Payment
R 1 000
New Monthly Payment
R 14 004
Original Total Interest
R 1 921 076
New Total Interest
R 1 425 066
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Extra Payment Impact (R1.5m Bond, 11.75%, 20 Years)
| Extra Monthly | Interest Saved | Time Saved |
|---|---|---|
| R500/month | ~R218,000 | ~2 yr 8 mo |
| R1,000/month | ~R384,000 | ~4 yr 8 mo |
| R2,000/month | ~R616,000 | ~7 yr 4 mo |
| R5,000/month | ~R990,000 | ~12 yr 2 mo |
Approximate figures. Actual savings depend on exact balance and timing.
Need more detail?
Extended Calculator More options, charts, and scenario comparison
R
%
R
Loan paid off in
14.0 years
Time saved
6.0 yrs
Total interest
R 1 558 418
Interest saved
R 842 927
Interest Paid: Without Extra vs With Extra
Strategies for Extra Payments
- Round up your payment: If your repayment is R15,670, round up to R16,000 — the R330 extra adds up significantly.
- Apply annual bonuses: A R30,000 year-end bonus as a lump sum can save years off your bond.
- Bimonthly payment trick: Pay half your monthly amount every two weeks — you end up making 13 full payments per year instead of 12.
- Increase payments when rates drop: When the prime rate falls, keep your payment at the higher level — the extra goes to principal.
Bond access facility: Many SA banks allow you to access extra payments you have made. This means you can overpay without losing liquidity — the extra builds up as an available credit line. Confirm this feature with your bank.
Need full precision?
Professional Calculator Complete parameters, sensitivity analysis, and detailed breakdown
Loan Details
R
%
Extra Payment Scenarios
R
R
R
%
JSE balanced fund ~10%
Strategy Comparison
R 2 401 345
Total interest without extra payments
| Extra/month | Time Saved | Interest Saved | Paid Off |
|---|---|---|---|
| None (baseline) | — | — | 20.0 yrs |
| R 1 000 | 3.7 yrs | R 527 838 | 16.3 yrs |
| R 2 500 | 6.9 yrs | R 959 589 | 13.1 yrs |
| R 5 000 | 9.9 yrs | R 1 339 499 | 10.1 yrs |
Opportunity Cost: Pay Off Bond vs Invest (10.0% return)
| Extra/month | Interest Saved | Investment Value | Better Strategy |
|---|---|---|---|
| R 1 000/mo | R 527 838 | R 759 369 | Invest |
| R 2 500/mo | R 959 589 | R 1 898 422 | Invest |
| R 5 000/mo | R 1 339 499 | R 3 796 844 | Invest |
At 11.8% bond rate vs 10.0% investment return. If your investment return exceeds your bond rate, investing may generate more wealth — but guaranteed bond savings carry zero risk.
Year-by-Year Balance (Scenario 2: +R 2 500/mo)
| Year | Balance | Interest Paid | Principal Paid |
|---|---|---|---|
| Year 1 | R 1 448 466 | R 173 533 | R 51 534 |
| Year 2 | R 1 390 540 | R 167 141 | R 57 926 |
| Year 3 | R 1 325 428 | R 159 956 | R 65 111 |
| Year 4 | R 1 252 241 | R 151 880 | R 73 188 |
| Year 5 | R 1 169 975 | R 142 801 | R 82 266 |
| Year 6 | R 1 077 505 | R 132 597 | R 92 470 |
| Year 7 | R 973 565 | R 121 127 | R 103 940 |
| Year 8 | R 856 732 | R 108 235 | R 116 833 |
| Year 9 | R 725 408 | R 93 743 | R 131 324 |
| Year 10 | R 577 795 | R 77 454 | R 147 614 |
| Year 11 | R 411 871 | R 59 144 | R 165 923 |
| Year 12 | R 225 367 | R 38 563 | R 186 504 |
| Year 13 | R 15 728 | R 15 429 | R 209 638 |
| Year 14 | R 0 | R 154 | R 15 728 |
Frequently Asked Questions
Extra bond payments can save enormous amounts. On a R1.5m bond at 11.75% over 20 years, an extra R1,000/month saves approximately R384,000 in interest and cuts the repayment period by about 4 years and 8 months. Even R500/month extra saves around R220,000.
Yes. South African banks allow extra payments on home loans. Most banks have a "bond access facility" where you can access the extra funds if needed later (like a revolving credit). Confirm with your bank that extra payments reduce the principal (not just future payments).
If your bond rate is 11.75% and you can earn more than 11.75% after tax on investments, investing wins mathematically. However, reducing your bond is a guaranteed return equal to the interest rate. For many South Africans, paying extra on the bond is the best risk-adjusted choice, especially in the early years.
A once-off lump sum (from a bonus, inheritance, or asset sale) applied to your bond principal immediately reduces interest for the remainder of the loan. It is often more impactful than regular extra payments of the same total value, because the full amount starts reducing interest immediately.