5 proven strategies
Popular prepayment strategies
The four most effective mortgage prepayment strategies are: biweekly payments (one extra full payment per year), rounding up the monthly amount (e.g. $1,398 → $1,500 saves $30,000+ over a 30-year loan), making early lump-sum payments ($5,000 in year 1 saves $15,000+), and combining strategies. Biweekly works best when budget-neutral; rounding up requires no behavioural change.
Key takeaways
04 · ideas- Biweekly = 1 extra payment/year without noticing
- Rounding up $1,398 → $1,500 saves $30k+
- A $5k lump sum early saves $15k+
- Combine strategies for maximum impact
Illustrative chart
$200k · 7.5% · 30yr
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Basic level
The essentials · 1 min
Five strategies, from simplest to most powerful:
- Round up your payment: $1,398 → $1,500 (+$102/mo)
- Fixed monthly extra: add $300 or $500 every month
- Biweekly payments: pay half your monthly payment every 2 weeks
- Lump-sum payments: direct bonuses or windfalls to principal
- Combination: mix monthly extra + annual lump sum
Pick the one that fits your budget and automate it.
Intermediate level
How it applies · 2 min
Comparing all 5 strategies — $200,000 at 7.5%, 30 years
| Strategy | Extra/year | Interest saved | Time saved |
|---|---|---|---|
| None | $0 | $0 | — |
| Round up (+$102/mo) | $1,224 | ~$30,800 | ~2.5 years |
| Extra $300/mo | $3,600 | ~$86,000 | ~4 years |
| Biweekly ($699 × 26) | ~$1,398 | ~$37,000 | ~2.8 years |
| $5k lump sum/yr | $5,000 | ~$80,000 | ~3.5 years |
| $300/mo + $3k/yr | $6,600 | ~$120,000 | ~5 years |
- Biweekly = 26 half-payments = 13 full payments/year = 1 extra month/year
- That extra month (~$1,398) applied to principal saves ~$37,000 over the loan
- This is equivalent to a $116/month fixed extra — without feeling it
Best bang for buck: The $300/mo extra has the best ratio of effort to savings for most households.
Advanced level
The math, step by step · 1 min
Optimization: highest-return strategy for your cash flow
Given an annual budget B, the optimal strategy maximizes \Delta I subject to total extra \leq B.
Monthly vs. annual comparison (same B = \3{,}600$/year):
$$\Delta I_{\text{monthly}} > \Delta I_{\text{quarterly}} > \Delta I_{\text{annually}}$$
The advantage of monthly over annual frequency is approximately:
$$\Delta\Delta I \approx e \cdot r \cdot \frac{11}{2} \cdot \mu$$
where e = B/12 is the monthly extra, and \mu is the remaining balance multiplier. The factor \frac{11}{2} captures the average months of advance application.
For B = \3{,}600$/year at 7.5%:
| Strategy | Interest saved |
|---|---|
| Monthly ($300/mo) | $85,900 |
| Hybrid ($150/mo + $1,800/yr) | $82,100 |
| Annual ($3,600/yr) | $77,200 |