Equal Principal Payment Amortization Calculator

Build a schedule where each payment repays the same slice of principal plus interest on the balance, so payments start high and fall every period.

Principal in every payment: $833.33
Last payment: $837.50
Total interest: $30,250.00
Level monthly payment: $1,110.21standard amortizing loan, same rate and term
Interest saved vs. level: $2,974.60
Drops below level payment: from payment #55
Final payment date: Oct 10, 2036

First payment$1,333.33falling by $4.17 each month to $837.50

Show the work

Principal per payment = $100,000.00 ÷ 120 = $833.33
Rate per period i = 6% ÷ 12 = 0.005
Payment 1 = $833.33 + $100,000.00 × 0.005 = $1,333.33
Each payment is $833.33 × 0.005 = $4.17 smaller; payment 120 = $833.33 + $833.33 × 0.005 = $837.50
Total interest = i × P × (n + 1) ÷ 2 = 0.005 × $100,000.00 × 121 ÷ 2 = $30,250.00

Payment size: equal principal vs. level payment

Equal principal
Level payment

Amortization schedule by year
Year	Ends	Payments	Principal	Interest	Balance
1	Oct 10, 2027	$15,725.00	$10,000.00	$5,725.00	$90,000.00
2	Oct 10, 2028	$15,125.00	$10,000.00	$5,125.00	$80,000.00
3	Oct 10, 2029	$14,525.00	$10,000.00	$4,525.00	$70,000.00
4	Oct 10, 2030	$13,925.00	$10,000.00	$3,925.00	$60,000.00
5	Oct 10, 2031	$13,325.00	$10,000.00	$3,325.00	$50,000.00
6	Oct 10, 2032	$12,725.00	$10,000.00	$2,725.00	$40,000.00
7	Oct 10, 2033	$12,125.00	$10,000.00	$2,125.00	$30,000.00
8	Oct 10, 2034	$11,525.00	$10,000.00	$1,525.00	$20,000.00
9	Oct 10, 2035	$10,925.00	$10,000.00	$925.00	$10,000.00
10	Oct 10, 2036	$10,325.00	$10,000.00	$325.00	$0.00
Total		$130,250.00	$100,000.00	$30,250.00

Equal principal schedule (monthly payments)
#	Date	Payment	Principal	Interest	Balance
1	Nov 10, 2026	$1,333.33	$833.33	$500.00	$99,166.67
2	Dec 10, 2026	$1,329.17	$833.33	$495.83	$98,333.33
3	Jan 10, 2027	$1,325.00	$833.33	$491.67	$97,500.00
4	Feb 10, 2027	$1,320.83	$833.33	$487.50	$96,666.67
5	Mar 10, 2027	$1,316.67	$833.33	$483.33	$95,833.33
6	Apr 10, 2027	$1,312.50	$833.33	$479.17	$95,000.00
7	May 10, 2027	$1,308.33	$833.33	$475.00	$94,166.67
8	Jun 10, 2027	$1,304.17	$833.33	$470.83	$93,333.33
9	Jul 10, 2027	$1,300.00	$833.33	$466.67	$92,500.00
10	Aug 10, 2027	$1,295.83	$833.33	$462.50	$91,666.67
11	Sep 10, 2027	$1,291.67	$833.33	$458.33	$90,833.33
12	Oct 10, 2027	$1,287.50	$833.33	$454.17	$90,000.00
13	Nov 10, 2027	$1,283.33	$833.33	$450.00	$89,166.67
14	Dec 10, 2027	$1,279.17	$833.33	$445.83	$88,333.33
15	Jan 10, 2028	$1,275.00	$833.33	$441.67	$87,500.00
16	Feb 10, 2028	$1,270.83	$833.33	$437.50	$86,666.67
17	Mar 10, 2028	$1,266.67	$833.33	$433.33	$85,833.33
18	Apr 10, 2028	$1,262.50	$833.33	$429.17	$85,000.00
19	May 10, 2028	$1,258.33	$833.33	$425.00	$84,166.67
20	Jun 10, 2028	$1,254.17	$833.33	$420.83	$83,333.33
21	Jul 10, 2028	$1,250.00	$833.33	$416.67	$82,500.00
22	Aug 10, 2028	$1,245.83	$833.33	$412.50	$81,666.67
23	Sep 10, 2028	$1,241.67	$833.33	$408.33	$80,833.33
24	Oct 10, 2028	$1,237.50	$833.33	$404.17	$80,000.00
25	Nov 10, 2028	$1,233.33	$833.33	$400.00	$79,166.67
26	Dec 10, 2028	$1,229.17	$833.33	$395.83	$78,333.33
27	Jan 10, 2029	$1,225.00	$833.33	$391.67	$77,500.00
28	Feb 10, 2029	$1,220.83	$833.33	$387.50	$76,666.67
29	Mar 10, 2029	$1,216.67	$833.33	$383.33	$75,833.33
30	Apr 10, 2029	$1,212.50	$833.33	$379.17	$75,000.00
31	May 10, 2029	$1,208.33	$833.33	$375.00	$74,166.67
32	Jun 10, 2029	$1,204.17	$833.33	$370.83	$73,333.33
33	Jul 10, 2029	$1,200.00	$833.33	$366.67	$72,500.00
34	Aug 10, 2029	$1,195.83	$833.33	$362.50	$71,666.67
35	Sep 10, 2029	$1,191.67	$833.33	$358.33	$70,833.33
36	Oct 10, 2029	$1,187.50	$833.33	$354.17	$70,000.00
37	Nov 10, 2029	$1,183.33	$833.33	$350.00	$69,166.67
38	Dec 10, 2029	$1,179.17	$833.33	$345.83	$68,333.33
39	Jan 10, 2030	$1,175.00	$833.33	$341.67	$67,500.00
40	Feb 10, 2030	$1,170.83	$833.33	$337.50	$66,666.67
41	Mar 10, 2030	$1,166.67	$833.33	$333.33	$65,833.33
42	Apr 10, 2030	$1,162.50	$833.33	$329.17	$65,000.00
43	May 10, 2030	$1,158.33	$833.33	$325.00	$64,166.67
44	Jun 10, 2030	$1,154.17	$833.33	$320.83	$63,333.33
45	Jul 10, 2030	$1,150.00	$833.33	$316.67	$62,500.00
46	Aug 10, 2030	$1,145.83	$833.33	$312.50	$61,666.67
47	Sep 10, 2030	$1,141.67	$833.33	$308.33	$60,833.33
48	Oct 10, 2030	$1,137.50	$833.33	$304.17	$60,000.00
49	Nov 10, 2030	$1,133.33	$833.33	$300.00	$59,166.67
50	Dec 10, 2030	$1,129.17	$833.33	$295.83	$58,333.33
51	Jan 10, 2031	$1,125.00	$833.33	$291.67	$57,500.00
52	Feb 10, 2031	$1,120.83	$833.33	$287.50	$56,666.67
53	Mar 10, 2031	$1,116.67	$833.33	$283.33	$55,833.33
54	Apr 10, 2031	$1,112.50	$833.33	$279.17	$55,000.00
55	May 10, 2031	$1,108.33	$833.33	$275.00	$54,166.67
56	Jun 10, 2031	$1,104.17	$833.33	$270.83	$53,333.33
57	Jul 10, 2031	$1,100.00	$833.33	$266.67	$52,500.00
58	Aug 10, 2031	$1,095.83	$833.33	$262.50	$51,666.67
59	Sep 10, 2031	$1,091.67	$833.33	$258.33	$50,833.33
60	Oct 10, 2031	$1,087.50	$833.33	$254.17	$50,000.00
61	Nov 10, 2031	$1,083.33	$833.33	$250.00	$49,166.67
62	Dec 10, 2031	$1,079.17	$833.33	$245.83	$48,333.33
63	Jan 10, 2032	$1,075.00	$833.33	$241.67	$47,500.00
64	Feb 10, 2032	$1,070.83	$833.33	$237.50	$46,666.67
65	Mar 10, 2032	$1,066.67	$833.33	$233.33	$45,833.33
66	Apr 10, 2032	$1,062.50	$833.33	$229.17	$45,000.00
67	May 10, 2032	$1,058.33	$833.33	$225.00	$44,166.67
68	Jun 10, 2032	$1,054.17	$833.33	$220.83	$43,333.33
69	Jul 10, 2032	$1,050.00	$833.33	$216.67	$42,500.00
70	Aug 10, 2032	$1,045.83	$833.33	$212.50	$41,666.67
71	Sep 10, 2032	$1,041.67	$833.33	$208.33	$40,833.33
72	Oct 10, 2032	$1,037.50	$833.33	$204.17	$40,000.00
73	Nov 10, 2032	$1,033.33	$833.33	$200.00	$39,166.67
74	Dec 10, 2032	$1,029.17	$833.33	$195.83	$38,333.33
75	Jan 10, 2033	$1,025.00	$833.33	$191.67	$37,500.00
76	Feb 10, 2033	$1,020.83	$833.33	$187.50	$36,666.67
77	Mar 10, 2033	$1,016.67	$833.33	$183.33	$35,833.33
78	Apr 10, 2033	$1,012.50	$833.33	$179.17	$35,000.00
79	May 10, 2033	$1,008.33	$833.33	$175.00	$34,166.67
80	Jun 10, 2033	$1,004.17	$833.33	$170.83	$33,333.33
81	Jul 10, 2033	$1,000.00	$833.33	$166.67	$32,500.00
82	Aug 10, 2033	$995.83	$833.33	$162.50	$31,666.67
83	Sep 10, 2033	$991.67	$833.33	$158.33	$30,833.33
84	Oct 10, 2033	$987.50	$833.33	$154.17	$30,000.00
85	Nov 10, 2033	$983.33	$833.33	$150.00	$29,166.67
86	Dec 10, 2033	$979.17	$833.33	$145.83	$28,333.33
87	Jan 10, 2034	$975.00	$833.33	$141.67	$27,500.00
88	Feb 10, 2034	$970.83	$833.33	$137.50	$26,666.67
89	Mar 10, 2034	$966.67	$833.33	$133.33	$25,833.33
90	Apr 10, 2034	$962.50	$833.33	$129.17	$25,000.00
91	May 10, 2034	$958.33	$833.33	$125.00	$24,166.67
92	Jun 10, 2034	$954.17	$833.33	$120.83	$23,333.33
93	Jul 10, 2034	$950.00	$833.33	$116.67	$22,500.00
94	Aug 10, 2034	$945.83	$833.33	$112.50	$21,666.67
95	Sep 10, 2034	$941.67	$833.33	$108.33	$20,833.33
96	Oct 10, 2034	$937.50	$833.33	$104.17	$20,000.00
97	Nov 10, 2034	$933.33	$833.33	$100.00	$19,166.67
98	Dec 10, 2034	$929.17	$833.33	$95.83	$18,333.33
99	Jan 10, 2035	$925.00	$833.33	$91.67	$17,500.00
100	Feb 10, 2035	$920.83	$833.33	$87.50	$16,666.67
101	Mar 10, 2035	$916.67	$833.33	$83.33	$15,833.33
102	Apr 10, 2035	$912.50	$833.33	$79.17	$15,000.00
103	May 10, 2035	$908.33	$833.33	$75.00	$14,166.67
104	Jun 10, 2035	$904.17	$833.33	$70.83	$13,333.33
105	Jul 10, 2035	$900.00	$833.33	$66.67	$12,500.00
106	Aug 10, 2035	$895.83	$833.33	$62.50	$11,666.67
107	Sep 10, 2035	$891.67	$833.33	$58.33	$10,833.33
108	Oct 10, 2035	$887.50	$833.33	$54.17	$10,000.00
109	Nov 10, 2035	$883.33	$833.33	$50.00	$9,166.67
110	Dec 10, 2035	$879.17	$833.33	$45.83	$8,333.33
111	Jan 10, 2036	$875.00	$833.33	$41.67	$7,500.00
112	Feb 10, 2036	$870.83	$833.33	$37.50	$6,666.67
113	Mar 10, 2036	$866.67	$833.33	$33.33	$5,833.33
114	Apr 10, 2036	$862.50	$833.33	$29.17	$5,000.00
115	May 10, 2036	$858.33	$833.33	$25.00	$4,166.67
116	Jun 10, 2036	$854.17	$833.33	$20.83	$3,333.33
117	Jul 10, 2036	$850.00	$833.33	$16.67	$2,500.00
118	Aug 10, 2036	$845.83	$833.33	$12.50	$1,666.67
119	Sep 10, 2036	$841.67	$833.33	$8.33	$833.33
120	Oct 10, 2036	$837.50	$833.33	$4.17	$0.00
Total		$130,250.00	$100,000.00	$30,250.00

Most consumer loans in the US use level payments: the same amount every month, with the interest share shrinking over time. An equal principal loan flips that: the principal part is fixed and the interest is paid on top, so the payment is highest at the start and falls with every installment. This calculator builds the full schedule and compares it with a level-payment loan at the same rate and term.

How to use the equal principal calculator

Enter the loan amount and the yearly interest rate.
Enter the term in years or months.
Choose monthly, quarterly, semi-annual or annual payments.
Optionally add the first payment date.
Compare the first and last payments, the chart against a level payment, and the yearly and per-payment schedules.

Equal principal formulas

With loan amount P, n payments and rate i per period (annual rate ÷ payments per year), payment number k is:

principal = P ÷ n · interest_k = i × P × (n − k + 1) ÷ n

Each payment is smaller than the one before by the same amount, (P ÷ n) × i, and the total interest has a neat closed form:

total interest = i × P × (n + 1) ÷ 2

Worked example

A $100,000 loan at 6% for 10 years, repaid monthly (n = 120, i = 0.005):

Principal per payment: 100,000 ÷ 120 = $833.33

Payment 1: 833.33 + 100,000 × 0.005 = $1,333.33

Each payment falls by 833.33 × 0.005 = $4.17, ending at $837.50

Total interest: 0.005 × 100,000 × 121 ÷ 2 = $30,250.00

A level-payment loan on the same terms costs $1,110.21 a month and $33,224.60 in interest, so equal principal saves $2,974.60. The trade-off is cash flow: you pay $223 more than the level payment in the first month, and only from payment 55 onward is the equal principal payment the smaller of the two.

Equal principal vs. level payments

	Equal principal	Level payment
First payment	$1,333.33	$1,110.21
Last payment	$837.50	$1,110.21
Balance after 5 years	$50,000.00	about $57,400
Total interest	$30,250.00	$33,224.60

When the structure makes sense

Declining payments suit borrowers whose income is highest now — a business with strong current cash flow, or someone expecting expenses to rise later. They also build equity faster, which reduces risk if the asset loses value. On the other hand, the high early payments make qualifying harder, and a level-payment loan with voluntary extra principal can achieve similar savings with more flexibility.

Annual and quarterly payments

Farm and equipment loans often require one or two payments a year. With annual payments, the same $100,000 at 6% over 10 years starts at $16,000 and ends at $10,600, for $33,000 of interest — more than the monthly version because principal is repaid less often.

For a standard level-payment schedule with extra payments, use the amortization calculator. For balloon structures or mixed compounding, try the advanced loan calculator.

Estimates only. Lenders may compute interest by the day or round payments, which changes the figures slightly.

Frequently asked questions

What is an equal principal payment loan?

It is a loan where every payment repays the same amount of principal — the loan divided by the number of payments — plus interest on the balance still owed. Because the balance falls by a fixed amount each time, the interest and therefore the total payment decline steadily.

Is equal principal cheaper than a regular amortizing loan?

Yes, at the same rate and term. Principal is repaid faster in the early years, so less interest accrues. A $100,000, 6%, 10-year loan costs $30,250 in interest with equal principal payments versus $33,224.60 with level payments.

Why is the first payment so much higher?

The first payment carries interest on the full loan plus the fixed principal slice. In the example it is $1,333.33 compared with a level payment of $1,110.21. The payments fall below the level payment from month 55 onward.

Where are equal principal loans used?

They are common for commercial and agricultural loans, some business term loans and many mortgages outside the United States, where the structure is often called linear repayment. Some lenders offer it on request.

Is there a shortcut for total interest?

Yes. With n payments, rate i per period and loan P, total interest equals i × P × (n + 1) ÷ 2, because the balances form an arithmetic sequence. For the example that is 0.005 × 100,000 × 121 ÷ 2 = $30,250.

Last reviewed October 2026 by the CalcFluent editorial team. How we check our calculators.