HELOC vs Mortgage Calculator
Compare converting your HELOC to a fixed mortgage vs making extra principal payments. Uses the same methodology as the HELOC vs Fixed Mortgage analysis .
Your scenario
This amount will be used in the comparison table below. Leave at 0 to compare against HELOC-only strategy.
Key insights
Read full analysis$300,000 converted
Convert 100% to fixed mortgage
$1,567
vs $1,163 HELOC interest-only
$39,149
Over 5 years
Fixed conversion vs HELOC + extra payments
Converting $300,000 saves you $14,880 in interest compared to keeping everything in HELOC, even with extra payments.
Strategy 1: Conversion to fixed
Monthly payments at different conversion amounts.
| Amount converted | HELOC remaining | Mortgage P&I | HELOC interest | Total monthly |
|---|---|---|---|---|
| $0 | $300,000 | $0 | $1,163 | $1,163 |
| $50,000 | $250,000 | $261 | $969 | $1,230 |
| $100,000 | $200,000 | $522 | $775 | $1,297 |
| $150,000 | $150,000 | $783 | $581 | $1,365 |
| $200,000 | $100,000 | $1,045 | $388 | $1,432 |
| $250,000 | $50,000 | $1,306 | $194 | $1,500 |
| $300,000 | $0 | $1,567 | $0 | $1,567 |
5-year outcomes: Conversion
Principal paid, interest paid, and remaining debt over 5 years.
| Amount converted | Principal paid | Total interest | Interest saved vs HELOC | Remaining debt |
|---|---|---|---|---|
| $0 | $0 | $69,750 | $0 | $300,000 |
| $50,000 | $6,525 | $67,270 | $2,480 | $293,475 |
| $100,000 | $13,050 | $64,790 | $4,960 | $286,950 |
| $150,000 | $19,575 | $62,310 | $7,440 | $280,425 |
| $200,000 | $26,100 | $59,830 | $9,920 | $273,900 |
| $250,000 | $32,624 | $57,350 | $12,400 | $267,376 |
| $300,000 | $39,149 | $54,870 | $14,880 | $260,851 |
Strategy 2: HELOC + extra payments
Keep balance in HELOC and add a fixed extra principal payment each month.
| Extra payment | Starting interest | Avg monthly payment | Principal paid (5yr) | Balance after 5 years |
|---|---|---|---|---|
| $0 | $1,163 | $1,163 | $0 | $300,000 |
| $500 | $1,163 | $1,605 | $30,000 | $270,000 |
| $600 | $1,163 | $1,694 | $36,000 | $264,000 |
| $700 | $1,163 | $1,782 | $42,000 | $258,000 |
Strategy comparison
Compare all three strategies side-by-side with key metrics.
| Metric | Conversion $300,000 | HELOC Only (No conversion) | HELOC + Extra $500/month |
|---|---|---|---|
| Monthly payment | $1,567 | $1,163 | $1,605 |
| Total interest paid | $54,870 | $69,750 | $66,321 |
| Principal paid | $39,149 | $0 | $30,000 |
| Remaining debt | $260,851 | $300,000 | $270,000 |
| Interest vs HELOC only | −$14,880 Saved | — | −$3,429 Saved |
| Total amount paid | $94,020 | $69,750 | $96,321 |
Want more details?
Read the complete analysis with detailed methodology, formulas, risk scenarios, and real-world recommendations.