Simple interest loan calculator

Enter a loan amount, rate and term to see your monthly payment, total interest and how much an extra payment saves. Free, and the numbers never leave your browser.

Calculate your payment

Monthly payment: $495.03

Total interest: $4,701.80
Total paid: $29,701.80
Paid off in: 60 months
Interest per day at the start: $4.79

Amortization schedule

Monthly payment breakdown
Month	Payment	Interest	Principal	Balance
1	$495.03	$145.83	$349.20	$24,650.80
2	$495.03	$143.80	$351.23	$24,299.57
3	$495.03	$141.75	$353.28	$23,946.29
4	$495.03	$139.69	$355.34	$23,590.94
5	$495.03	$137.61	$357.42	$23,233.53
6	$495.03	$135.53	$359.50	$22,874.03
7	$495.03	$133.43	$361.60	$22,512.43
8	$495.03	$131.32	$363.71	$22,148.72
9	$495.03	$129.20	$365.83	$21,782.89
10	$495.03	$127.07	$367.96	$21,414.93
11	$495.03	$124.92	$370.11	$21,044.82
12	$495.03	$122.76	$372.27	$20,672.55
13	$495.03	$120.59	$374.44	$20,298.11
14	$495.03	$118.41	$376.62	$19,921.49
15	$495.03	$116.21	$378.82	$19,542.67
16	$495.03	$114.00	$381.03	$19,161.63
17	$495.03	$111.78	$383.25	$18,778.38
18	$495.03	$109.54	$385.49	$18,392.89
19	$495.03	$107.29	$387.74	$18,005.15
20	$495.03	$105.03	$390.00	$17,615.15
21	$495.03	$102.76	$392.27	$17,222.88
22	$495.03	$100.47	$394.56	$16,828.31
23	$495.03	$98.17	$396.86	$16,431.45
24	$495.03	$95.85	$399.18	$16,032.27
25	$495.03	$93.52	$401.51	$15,630.76
26	$495.03	$91.18	$403.85	$15,226.91
27	$495.03	$88.82	$406.21	$14,820.71
28	$495.03	$86.45	$408.58	$14,412.13
29	$495.03	$84.07	$410.96	$14,001.17
30	$495.03	$81.67	$413.36	$13,587.81
31	$495.03	$79.26	$415.77	$13,172.05
32	$495.03	$76.84	$418.19	$12,753.85
33	$495.03	$74.40	$420.63	$12,333.22
34	$495.03	$71.94	$423.09	$11,910.13
35	$495.03	$69.48	$425.55	$11,484.58
36	$495.03	$66.99	$428.04	$11,056.54
37	$495.03	$64.50	$430.53	$10,626.01
38	$495.03	$61.99	$433.04	$10,192.97
39	$495.03	$59.46	$435.57	$9,757.39
40	$495.03	$56.92	$438.11	$9,319.28
41	$495.03	$54.36	$440.67	$8,878.61
42	$495.03	$51.79	$443.24	$8,435.38
43	$495.03	$49.21	$445.82	$7,989.55
44	$495.03	$46.61	$448.42	$7,541.13
45	$495.03	$43.99	$451.04	$7,090.09
46	$495.03	$41.36	$453.67	$6,636.42
47	$495.03	$38.71	$456.32	$6,180.10
48	$495.03	$36.05	$458.98	$5,721.12
49	$495.03	$33.37	$461.66	$5,259.46
50	$495.03	$30.68	$464.35	$4,795.11
51	$495.03	$27.97	$467.06	$4,328.06
52	$495.03	$25.25	$469.78	$3,858.27
53	$495.03	$22.51	$472.52	$3,385.75
54	$495.03	$19.75	$475.28	$2,910.47
55	$495.03	$16.98	$478.05	$2,432.42
56	$495.03	$14.19	$480.84	$1,951.58
57	$495.03	$11.38	$483.65	$1,467.93
58	$495.03	$8.56	$486.47	$981.46
59	$495.03	$5.73	$489.30	$492.16
60	$495.03	$2.87	$492.16	$0.00

Estimates for a fixed-rate loan with equal monthly payments. Lenders that use daily simple interest charge interest on the exact days between payments, so paying early or late changes the interest slightly.

How this calculator works

A simple interest loan charges interest only on the principal you still owe, never on past interest. Each month:

Interest = remaining balance × APR ÷ 12. On $25,000 at 7%, the first month’s interest is $145.83.
Principal = your payment minus that interest. With a $495.03 payment, $349.20 reduces the balance.
The balance drops, so next month’s interest is a little smaller, and more of the same payment goes to principal.

That’s why the schedule shows interest shrinking every month, and why an extra $100 a month on that loan saves about $939 and ends it 11 months early. For the bare formula, I = P × r × t, see simple interest formula and examples. For auto loans that accrue interest by the day, see daily simple interest.

Compare simple interest personal loans

Most fixed-rate personal loans are simple interest loans. Prequalifying with a soft credit check lets you compare real rates before you apply. What to compare.

Option

Even Financial

A loan-matching marketplace that shows personal loan offers from multiple lenders after one prequalification form.

Best for: Comparing several lenders at once

Visit the provider’s own site to compare current pricing and terms.

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SuperMoney

A comparison marketplace for personal loans and other financial products, with prequalified offers from partner lenders.

Best for: Shopping rates without a hard credit pull to prequalify

Visit the provider’s own site to compare current pricing and terms.

Option

Upgrade

An online lender offering fixed-rate personal loans with fixed monthly payments.

Best for: Borrowers who want one direct lender

Visit the provider’s own site to compare current pricing and terms.

Frequently asked questions

How do you calculate a simple interest loan?

For the interest alone, multiply principal by the annual rate by the time in years: I = P × r × t. For a loan you repay monthly, interest each month is the remaining balance times the APR divided by 12, and the payment is set so the loan reaches zero at the end of the term. The calculator above does both. See the formula with worked examples.

What is the simple interest on $1,000 borrowed for 5 years at 5%?

$250. Using I = P × r × t: $1,000 × 0.05 × 5 = $250, so you would repay $1,250 in total if interest were charged on the original amount for the whole time. On a loan repaid monthly the interest is lower, about $132, because the balance shrinks as you pay.

Can I pay off a simple interest loan early?

Usually, yes, and it saves money, because interest is charged only on the balance you still owe. Check your contract for a prepayment penalty first. Use the “extra each month” box above, or read how paying early works.

Is a simple interest loan good or bad?

For borrowers it is usually the better structure: you never pay interest on interest, and extra payments cut your total cost right away. The trade-off with daily simple interest is that paying late costs a little more interest. More on how they work.