Line of Credit Calculator
See how draws and repayments change the interest and closing debt on a business or home equity line of credit.
Facility details
Transactions
Interest settings
The calculator also posts interest on the final day.
Results
Total interest
$165
Closing debt
$22,165
Credit remaining
$7,835
Total fees
$0
Principal payments
$3,000
Total interest $165. Closing debt $22,165.
Payment and limit check
| Measure | Amount |
|---|---|
| Closing excess over limit | $0.00 |
| Peak excess over limit | $0.00 |
| Unapplied repayments | $0.00 |
| Interest paid separately | $0 |
| Fees paid separately | $0 |
Balance and interest schedule
| Model days | Drawn balance | Interest accrued | Interest posted | Closing debt |
|---|---|---|---|---|
| 1 to 10 | $20,000.00 | $49.32 | $0.00 | $20,000.00 |
| 11 to 20 | $25,000.00 | $61.64 | $0.00 | $25,000.00 |
| 21 to 30 | $22,000.00 | $54.25 | $165.21 | $22,165.21 |
Closing debt by day
Closing debt is $22,165.21 at the end of day 30. The schedule shows the balance changes.
One entered rate applies throughout the model period, including to any balance above the entered limit.
Calculate Interest on a Changing Balance
The line of credit calculator multiplies each day’s drawn balance by your annual rate divided by the chosen day-count basis. It adds the daily amounts over the model period. Moneysmart’s guide to mortgage offset accounts explains how the daily balance affects interest on most home loans.
Enter the number of days that have already passed when a transaction takes effect. A draw after ten elapsed days first accrues interest on day 11. The calculator applies draws and fees added to debt first, then takes principal repayments off that day’s balance. Fees paid separately are counted on their entered day and stay outside the debt.
Interest posts after the day’s accrual at the interval you enter and again on the last day. Each posting rounds to cents. Added interest earns interest from the next day. Interest paid separately leaves the drawn balance unchanged. Under the CommBank business finance terms, the bank usually calculates interest on the second-last calendar day of the month and charges it the next day.
Model Business and Home-Equity Draws
A business can draw in stages as equipment invoices fall due, then repay principal when customers pay. A home equity line of credit can fund separate renovation bills from an existing facility. The facility label identifies the scenario and both use the same calculation.
Credit remaining is the entered limit less closing debt, floored at zero. The limit check shows how far closing debt sits above the entered limit and the largest excess during the period. The scenario uses a limit you supply. A lender decides the approved limit and whether to allow any excess.
A fixed amortising business loan starts with a set amount and reduces debt through scheduled principal and interest payments. This revolving schedule follows the transactions you enter. The usable equity calculator estimates the room to borrow against a property at an entered loan-to-value ratio.
Follow a Draw and Repayment Example
In the hypothetical 30-day example, the opening balance is $20,000 and the annual rate is 9% on an actual/365 basis. A $5,000 draw after ten days raises the balance to $25,000. A $3,000 principal payment after twenty days takes it to $22,000.
Each balance runs for ten days. Multiply the sum of $20,000, $25,000 and $22,000 by ten days and by 9% divided by 365. The final posting is $165.21. With the interest added to debt and no fees, the last schedule row shows $22,165.21 closing debt. The headline figures round to whole dollars.
Read the Interest and Credit Remaining
Use total interest and fees to read the cost, then check principal payments to see how much debt the repayments reduced. If you pay only interest from another account, the drawn balance stays the same. A principal payment above the debt stops at zero and the unused part appears under unapplied repayments.
An earlier draw or a later repayment leaves more days at the higher balance. A lender’s facility review can change the limit, and a rate change or a different interest posting date can change what the statement shows. Match the model to the agreement when checking actual charges.
