Loan payoff calculator

Compare your current monthly payment with a higher payment to see when the loan ends and how much interest you avoid. Amounts are shown in GBP for readability; this is a planning tool, not lender-accurate interest accrual.

Loan details

Loan amount (£)

Annual interest rate (%)

Base monthly payment (£)

Revised monthly payment (£)

First payment month (start date)

Interest model

Banks accrue daily and post interest on statement dates; payments may not be evenly spaced. “365-day months” usually tracks closer than APR ÷ 12, but will still not match every line on your app.

Extra lump sums (optional)

One per line: month number, amount — extra principal after that month’s payment (month 1 = first payment). Lines starting with # are ignored.

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Why this may not match your bank statement

Daily interest: Most UK loans accrue interest every day on the balance, then show it on a statement date. This tool uses one interest step per month (or the 365-day monthly option below), not day-by-day running balances.
Payment vs statement dates: If your payment moves (e.g. weekend, bank processing), you can get two interest charges between two payments, or a different number of days in each period. The calculator assumes a regular monthly rhythm from your start date.
Rounding and fees: Banks round at different points; some add fees or insurance. Totals here are illustrative.

Use the same APR and payment as on your paperwork for trend comparison (payoff timing, “what if I pay more”). For an exact payoff figure, ask your lender.

Base payment scenario

£500/mo

Payoff date: June 2071
Months to payoff: 544
Total interest: £171,701.74
Total paid (scheduled + lumps): £272,000.00

Revised payment scenario

£600/mo

Payoff date: June 2052
Months to payoff: 316
Total interest: £89,394.08
Total paid (scheduled + lumps): £189,600.00

Compared to the base payment

Months saved: 228

Interest saved: £82,307.66

Extra to principal each month is the difference between revised and base payment (everything above interest goes to balance).

Amortization schedule

#	Month	Balance start	Interest	Principal	Lump	Payment	Balance end
1	Mar 2026	£100,000.00	£458.33	£141.67	£0.00	£600.00	£99,858.33
2	Apr 2026	£99,858.33	£457.68	£142.32	£0.00	£600.00	£99,716.01
3	May 2026	£99,716.01	£457.03	£142.97	£0.00	£600.00	£99,573.04
4	Jun 2026	£99,573.04	£456.38	£143.62	£0.00	£600.00	£99,429.42
5	Jul 2026	£99,429.42	£455.72	£144.28	£0.00	£600.00	£99,285.14
6	Aug 2026	£99,285.14	£455.06	£144.94	£0.00	£600.00	£99,140.20
7	Sep 2026	£99,140.20	£454.39	£145.61	£0.00	£600.00	£98,994.59
8	Oct 2026	£98,994.59	£453.73	£146.27	£0.00	£600.00	£98,848.32
9	Nov 2026	£98,848.32	£453.05	£146.95	£0.00	£600.00	£98,701.37
10	Dec 2026	£98,701.37	£452.38	£147.62	£0.00	£600.00	£98,553.75
11	Jan 2027	£98,553.75	£451.70	£148.30	£0.00	£600.00	£98,405.45
12	Feb 2027	£98,405.45	£451.02	£148.98	£0.00	£600.00	£98,256.47
13	Mar 2027	£98,256.47	£450.34	£149.66	£0.00	£600.00	£98,106.81
14	Apr 2027	£98,106.81	£449.66	£150.34	£0.00	£600.00	£97,956.47

Showing first 14 of 316 rows. Toggle “Show full schedule” to see everything.