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Ammonization Calculator

Ammonization calculator works out Payment and Total interest from Loan amount, Annual interest rate and Loan term. The default figures on this page give payment of 158.02; change any entry and the result, the working and the sources update together.

Payment

158.02

Amortization Schedule Calculator

Total interest

31,883.81

Total of payments

56,883.81

Number of payments

360

Payoff time

30 years

Rate per period

0.541667 %

Interest per unit borrowed

1.2754

Interest saved by extra payments

Payments saved

Interest in the first payment

135.42

Principal in the first payment

22.6

Payment where principal overtakes interest

233

Payment where the balance is half repaid

257

Balance after one year

24,720.53

Worked out from Standard annuity-immediate payment formula, PMT = P i / (1 - (1+i)^-n) and 1 other source.

Your figures

Updates as you type

Display currencyFormatting only. This does not change the calculation.

Loan amount

Annual interest rate (%)The nominal annual rate (APR before fees), not the monthly rate.

Loan term (years)

Term - additional monthsAdded to the term in years, for terms such as 5 years and 6 months. To state a tenure purely in months, set the years to 0 and enter the whole tenure here.

Payment frequency

Extra payment each period Additional principal paid on top of the scheduled payment.

Include the amortisation schedule

How this is worked out

5 steps

Each period, interest = outstanding balance x 0.541667%; the rest of the payment reduces principal.
Payment 1: 135.42 interest and 22.6 principal.
From payment 233 onwards more of each payment goes to principal than to interest.
The balance is half repaid by payment 257.
Year 1 ends with 24720.53 outstanding, 1.12% of the loan retired.

Amortisation scheduletable

period	payment	interest	principal	balance
1	158.02	135.42	22.6	24,977.4
2	158.02	135.29	22.73	24,954.67
3	158.02	135.17	22.85	24,931.82
4	158.02	135.05	22.97	24,908.85
5	158.02	134.92	23.1	24,885.75
6	158.02	134.8	23.22	24,862.53
7	158.02	134.67	23.35	24,839.18
8	158.02	134.55	23.47	24,815.71
9	158.02	134.42	23.6	24,792.11
10	158.02	134.29	23.73	24,768.38
11	158.02	134.16	23.86	24,744.52
12	158.02	134.03	23.99	24,720.53
13	158.02	133.9	24.12	24,696.41
14	158.02	133.77	24.25	24,672.16
15	158.02	133.64	24.38	24,647.78
16	158.02	133.51	24.51	24,623.27
17	158.02	133.38	24.64	24,598.63
18	158.02	133.24	24.78	24,573.85
19	158.02	133.11	24.91	24,548.94
20	158.02	132.97	25.05	24,523.89
21	158.02	132.84	25.18	24,498.71
22	158.02	132.7	25.32	24,473.39
23	158.02	132.56	25.46	24,447.93
24	158.02	132.43	25.59	24,422.34
25	158.02	132.29	25.73	24,396.61
26	158.02	132.15	25.87	24,370.74
27	158.02	132.01	26.01	24,344.73
28	158.02	131.87	26.15	24,318.58
29	158.02	131.73	26.29	24,292.29
30	158.02	131.58	26.44	24,265.85
31	158.02	131.44	26.58	24,239.27
32	158.02	131.3	26.72	24,212.55
33	158.02	131.15	26.87	24,185.68
34	158.02	131.01	27.01	24,158.67
35	158.02	130.86	27.16	24,131.51
36	158.02	130.71	27.31	24,104.2
37	158.02	130.56	27.46	24,076.74
38	158.02	130.42	27.6	24,049.14
39	158.02	130.27	27.75	24,021.39
40	158.02	130.12	27.9	23,993.49
41	158.02	129.96	28.06	23,965.43
42	158.02	129.81	28.21	23,937.22
43	158.02	129.66	28.36	23,908.86
44	158.02	129.51	28.51	23,880.35
45	158.02	129.35	28.67	23,851.68
46	158.02	129.2	28.82	23,822.86
47	158.02	129.04	28.98	23,793.88
48	158.02	128.88	29.14	23,764.74
49	158.02	128.73	29.29	23,735.45
50	158.02	128.57	29.45	23,706
51	158.02	128.41	29.61	23,676.39
52	158.02	128.25	29.77	23,646.62
53	158.02	128.09	29.93	23,616.69
54	158.02	127.92	30.1	23,586.59
55	158.02	127.76	30.26	23,556.33
56	158.02	127.6	30.42	23,525.91
57	158.02	127.43	30.59	23,495.32
58	158.02	127.27	30.75	23,464.57
59	158.02	127.1	30.92	23,433.65
60	158.02	126.93	31.09	23,402.56
61	158.02	126.76	31.26	23,371.3
62	158.02	126.59	31.43	23,339.87
63	158.02	126.42	31.6	23,308.27
64	158.02	126.25	31.77	23,276.5
65	158.02	126.08	31.94	23,244.56
66	158.02	125.91	32.11	23,212.45
67	158.02	125.73	32.29	23,180.16
68	158.02	125.56	32.46	23,147.7
69	158.02	125.38	32.64	23,115.06
70	158.02	125.21	32.81	23,082.25
71	158.02	125.03	32.99	23,049.26
72	158.02	124.85	33.17	23,016.09
73	158.02	124.67	33.35	22,982.74
74	158.02	124.49	33.53	22,949.21
75	158.02	124.31	33.71	22,915.5
76	158.02	124.13	33.89	22,881.61
77	158.02	123.94	34.08	22,847.53
78	158.02	123.76	34.26	22,813.27
79	158.02	123.57	34.45	22,778.82
80	158.02	123.39	34.63	22,744.19
81	158.02	123.2	34.82	22,709.37
82	158.02	123.01	35.01	22,674.36
83	158.02	122.82	35.2	22,639.16
84	158.02	122.63	35.39	22,603.77
85	158.02	122.44	35.58	22,568.19
86	158.02	122.24	35.78	22,532.41
87	158.02	122.05	35.97	22,496.44
88	158.02	121.86	36.16	22,460.28
89	158.02	121.66	36.36	22,423.92
90	158.02	121.46	36.56	22,387.36
91	158.02	121.26	36.76	22,350.6
92	158.02	121.07	36.95	22,313.65
93	158.02	120.87	37.15	22,276.5
94	158.02	120.66	37.36	22,239.14
95	158.02	120.46	37.56	22,201.58
96	158.02	120.26	37.76	22,163.82
97	158.02	120.05	37.97	22,125.85
98	158.02	119.85	38.17	22,087.68
99	158.02	119.64	38.38	22,049.3
100	158.02	119.43	38.59	22,010.71
101	158.02	119.22	38.8	21,971.91
102	158.02	119.01	39.01	21,932.9
103	158.02	118.8	39.22	21,893.68
104	158.02	118.59	39.43	21,854.25
105	158.02	118.38	39.64	21,814.61
106	158.02	118.16	39.86	21,774.75
107	158.02	117.95	40.07	21,734.68
108	158.02	117.73	40.29	21,694.39
109	158.02	117.51	40.51	21,653.88
110	158.02	117.29	40.73	21,613.15
111	158.02	117.07	40.95	21,572.2
112	158.02	116.85	41.17	21,531.03
113	158.02	116.63	41.39	21,489.64
114	158.02	116.4	41.62	21,448.02
115	158.02	116.18	41.84	21,406.18
116	158.02	115.95	42.07	21,364.11
117	158.02	115.72	42.3	21,321.81
118	158.02	115.49	42.53	21,279.28
119	158.02	115.26	42.76	21,236.52
120	158.02	115.03	42.99	21,193.53

First 120 of 360 rows.

Yearly summarytable

year	interest	principal	endingBalance
1	1,616.77	279.47	24,720.53
2	1,598.05	298.19	24,422.34
3	1,578.1	318.14	24,104.2
4	1,556.78	339.46	23,764.74
5	1,534.06	362.18	23,402.56
6	1,509.77	386.47	23,016.09
7	1,483.92	412.32	22,603.77
8	1,456.29	439.95	22,163.82
9	1,426.81	469.43	21,694.39
10	1,395.38	500.86	21,193.53
11	1,361.82	534.42	20,659.11
12	1,326.05	570.19	20,088.92
13	1,287.85	608.39	19,480.53
14	1,247.13	649.11	18,831.42
15	1,203.64	692.6	18,138.82
16	1,157.26	738.98	17,399.84
17	1,107.77	788.47	16,611.37
18	1,054.98	841.26	15,770.11
19	998.63	897.61	14,872.5
20	938.52	957.72	13,914.78
21	874.36	1,021.88	12,892.9
22	805.94	1,090.3	11,802.6
23	732.91	1,163.33	10,639.27
24	655.02	1,241.22	9,398.05
25	571.9	1,324.34	8,073.71
26	483.2	1,413.04	6,660.67
27	388.55	1,507.69	5,152.98
28	287.6	1,608.64	3,544.34
29	179.86	1,716.38	1,827.96
30	64.89	1,827.96	0

Chart series, one row a yeartable

year	interest	principal	cumulativeInterest	cumulativePrincipal	endingBalance	percentPaidOff
1	1,616.77	279.47	1,616.77	279.47	24,720.53	1.12
2	1,598.05	298.19	3,214.82	577.66	24,422.34	2.31
3	1,578.1	318.14	4,792.92	895.8	24,104.2	3.58
4	1,556.78	339.46	6,349.7	1,235.26	23,764.74	4.94
5	1,534.06	362.18	7,883.76	1,597.44	23,402.56	6.39
6	1,509.77	386.47	9,393.53	1,983.91	23,016.09	7.94
7	1,483.92	412.32	10,877.45	2,396.23	22,603.77	9.58
8	1,456.29	439.95	12,333.74	2,836.18	22,163.82	11.34
9	1,426.81	469.43	13,760.55	3,305.61	21,694.39	13.22
10	1,395.38	500.86	15,155.93	3,806.47	21,193.53	15.23
11	1,361.82	534.42	16,517.75	4,340.89	20,659.11	17.36
12	1,326.05	570.19	17,843.8	4,911.08	20,088.92	19.64
13	1,287.85	608.39	19,131.65	5,519.47	19,480.53	22.08
14	1,247.13	649.11	20,378.78	6,168.58	18,831.42	24.67
15	1,203.64	692.6	21,582.42	6,861.18	18,138.82	27.44
16	1,157.26	738.98	22,739.68	7,600.16	17,399.84	30.4
17	1,107.77	788.47	23,847.45	8,388.63	16,611.37	33.55
18	1,054.98	841.26	24,902.43	9,229.89	15,770.11	36.92
19	998.63	897.61	25,901.06	10,127.5	14,872.5	40.51
20	938.52	957.72	26,839.58	11,085.22	13,914.78	44.34
21	874.36	1,021.88	27,713.94	12,107.1	12,892.9	48.43
22	805.94	1,090.3	28,519.88	13,197.4	11,802.6	52.79
23	732.91	1,163.33	29,252.79	14,360.73	10,639.27	57.44
24	655.02	1,241.22	29,907.81	15,601.95	9,398.05	62.41
25	571.9	1,324.34	30,479.71	16,926.29	8,073.71	67.71
26	483.2	1,413.04	30,962.91	18,339.33	6,660.67	73.36
27	388.55	1,507.69	31,351.46	19,847.02	5,152.98	79.39
28	287.6	1,608.64	31,639.06	21,455.66	3,544.34	85.82
29	179.86	1,716.38	31,818.92	23,172.04	1,827.96	92.69
30	64.89	1,827.96	31,883.81	25,000	0	100

Its 4 worked examples are re-run on every release, last on 15 September 2026. What changed

Sources and references

2 sources

Standard annuity-immediate payment formula, PMT = P i / (1 - (1+i)^-n)

Equivalent to the Excel PMT function and to the actuarial present value of a level annuity.

12 CFR Part 1026 (Regulation Z), Appendix J - Annual Percentage Rate Computations

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Save it, change one figure, then compare the two

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What the ammonization calculator calculates

Builds the full period-by-period amortisation table for a loan, showing how each payment splits between interest and principal.

How to use this ammonization calculator

Enter Loan amount, Annual interest rate, Loan term and Term - additional months. Payment updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.

How the result is worked out

Open “How this is worked out” beside the result for the step-by-step calculation behind Payment, Total interest and Total of payments.

The method follows Standard annuity-immediate payment formula, PMT = P i / (1 - (1+i)^-n) and 12 CFR Part 1026 (Regulation Z), Appendix J - Annual Percentage Rate Computations.

First payment split on 300k at 5% example

With Loan amount: 300000, Annual interest rate: 5, Loan term: 30, the calculator returns Interest in the first payment: 1250, Principal in the first payment: 360.46. This example is checked against an independent source in the test suite.

What you can compare

Change one input at a time to see how it affects Payment, Total interest and Total of payments. The inputs you can vary are Loan amount, Annual interest rate, Loan term, Term - additional months, Payment frequency and Extra payment each period.

Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.

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Copy this code into any page. The calculator appears with the figures currently entered, sizes itself to fit, and a small credit line links back here. Free, no account, no ads inside it, no tracking of your readers. Set your own figures and fixed fields; Personal removes the credit line, sets your colour and shows you which sites use it.

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Frequently asked questions

What information do I need for the ammonization calculator?

You need Loan amount, Annual interest rate, Loan term, Term - additional months, Payment frequency and Extra payment each period. The page opens with default figures that give payment of 158.02, so you can see the scale before entering your own.

What does this ammonization calculator show?

It shows Payment, Total interest, Total of payments, Number of payments, Payoff time, Rate per period, Interest per unit borrowed and Interest saved by extra payments, with the working and any warnings for your entries.

Can I check how the ammonization calculator result was calculated?

Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.

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