HELOC Calculator — Draw Period, Repayment Payment & Interest Cost
A HELOC calculator estimates interest-only draw payments and the later amortizing payment. Three examples: (1) $40,000 drawn at 8% → about $267/month interest-only; then ~$335/month over 10 years once amortizing. (2) $75,000 at 7.5% → about $469 IO; then ~$695/month over 15 years. (3) $100,000 at 8% → about $667 IO; then ~$836/month over 20 years. Rates are often variable — update inputs when your margin or index changes.
Draw Period Payment
$531/mo
- Repayment Period Payment
- $651/mo
- Total Interest (draw)
- $63,750
- Total Interest (repayment)
- $81,208
- Total Interest (combined)
- $144,958
HELOC Repayment Schedule (Annual Summary)
| Year | Payments | Interest | Principal | Ending balance |
|---|---|---|---|---|
| 1 | $7,810 | $6,318 | $1,493 | $73,507 |
| 2 | $7,810 | $6,186 | $1,625 | $71,883 |
| 3 | $7,810 | $6,042 | $1,768 | $70,115 |
| 4 | $7,810 | $5,886 | $1,925 | $68,190 |
| 5 | $7,810 | $5,716 | $2,095 | $66,095 |
| 6 | $7,810 | $5,531 | $2,280 | $63,816 |
| 7 | $7,810 | $5,329 | $2,481 | $61,334 |
| 8 | $7,810 | $5,110 | $2,701 | $58,634 |
| 9 | $7,810 | $4,871 | $2,939 | $55,694 |
| 10 | $7,810 | $4,611 | $3,199 | $52,495 |
Methodology and limitations
Last reviewed:
Methodology
Models interest-only or amortizing draw period plus amortizing repayment on drawn balance.
Limitations
Variable rates, lender margins, fees, and draw restrictions not fully modeled.
Official sources
How to Use the HELOC Calculator — Draw Period, Repayment Payment & Interest Cost
A HELOC calculator estimates interest-only draw payments and the later amortizing payment. Three examples: (1) $40,000 drawn at 8% → about $267/month interest-only; then ~$335/month over 10 years once amortizing. (2) $75,000 at 7.5% → about $469 IO; then ~$695/month over 15 years. (3) $100,000 at 8% → about $667 IO; then ~$836/month over 20 years. Rates are often variable — update inputs when your margin or index changes.
Method used
Models draw-period payments (interest-only or amortizing) and repayment-period amortization.
Practical example
Example: $75,000 drawn on $100,000 line at 8.5% — compare draw vs repayment payment.
What this includes
- Includes draw and repayment phase estimates.
- Uses entered APR for planning.
What this excludes
- Variable rate changes and lender fees not fully modeled.
Frequently Asked Questions
What is a HELOC draw period?
The draw period is when you can borrow from the line and often pay interest-only on the amount drawn. Typical draw periods run about 10 years. On $40,000 at 8%, interest-only is about $267/month; after draw ends, a 10-year amortizing payment on the same balance is roughly $335/month. Model both phases here before you rely on the lower IO payment.
How is HELOC interest calculated?
Most HELOCs use a variable rate (index + margin) with interest accruing daily on the outstanding balance. Interest-only payment ≈ balance × (annual rate ÷ 12). Example: $75,000 at 7.5% is about $469/month IO; the same balance amortized over 15 years is roughly $695/month. Recalculate when your rate adjusts.
HELOC vs home equity loan — which is cheaper?
A home equity loan is a fixed lump sum with fixed payments; a HELOC offers flexible draws and often variable rates. HELOCs can cost less during interest-only draw — e.g. ~$667/month IO on $100,000 at 8% — but may cost more if rates rise or you carry a large balance into repayment (~$836/month over 20 years at the same rate). Compare total interest across both structures.
Can I get a HELOC amortization schedule?
During repayment, a HELOC amortizes like a standard loan. During interest-only draw, principal stays flat unless you pay extra. Example: $75,000 at 7.5% stays near $469/month IO until repayment starts, then jumps toward ~$695/month over 15 years. Use this tool for phase estimates; use the amortization calculator for a full month-by-month fixed-installment table.
What credit line limit do I need?
Lenders typically cap combined mortgage plus HELOC debt around 80–90% of home value, minus the first mortgage. Available credit depends on appraisal, income, and credit. Enter your planned draw — $40k, $75k, or $100k in the examples above — to estimate IO and amortizing payments before you apply.