What is the Rule of 72?

Divide 72 by your interest rate to estimate doubling time. At 7%, money doubles about every 10.3 years.

Why does compounding frequency matter?

More frequent compounding credits interest sooner, so interest earns interest faster. Monthly beats annual at the same nominal rate.

Compound Interest Calculator

Harness the power of compounding. Project how savings and investments grow with regular contributions and compound interest, with a year-by-year breakdown of contributions vs. interest earned.

#compound interest#investment growth#savings#future value#interest calculator

Live calculate

Presets

Initial Investment

Regular Contribution

Contribution Frequency

MonthlyQuarterlyAnnual

Interest Rate

% / year

Years to Grow

years

Compounding Frequency

Live mode: results update as you type.

Future Balance

$302,370

after 20 years at 7.00% compounded monthly

Initial Investment: $10,000
Total Contributions: $120,000
Total Interest Earned: $172,370
Final Balance: $302,370
Growth Multiple: 2.33×
Interest Share of Balance: 57.0%

Balance composition

Initial$10,000
Contributions$120,000
Interest$172,370

Year-by-year growth

Year	Balance	Cumulative Contributions	Cumulative Interest	Interest This Path
Year 1	$16,955	$6,000	$955	$955
Year 2	$24,413	$12,000	$2,413	$2,413
Year 3	$32,411	$18,000	$4,411	$4,411
Year 4	$40,986	$24,000	$6,986	$6,986
Year 5	$50,182	$30,000	$10,182	$10,182
Year 6	$60,042	$36,000	$14,042	$14,042
Year 7	$70,614	$42,000	$18,614	$18,614
Year 8	$81,952	$48,000	$23,952	$23,952
Year 9	$94,108	$54,000	$30,108	$30,108
Year 10	$107,144	$60,000	$37,144	$37,144
Year 11	$121,122	$66,000	$45,122	$45,122
Year 12	$136,110	$72,000	$54,110	$54,110
Year 13	$152,182	$78,000	$64,182	$64,182
Year 14	$169,416	$84,000	$75,416	$75,416
Year 15	$187,895	$90,000	$87,895	$87,895
Year 16	$207,710	$96,000	$101,710	$101,710
Year 17	$228,958	$102,000	$116,958	$116,958
Year 18	$251,742	$108,000	$133,742	$133,742
Year 19	$276,173	$114,000	$152,173	$152,173
Year 20	$302,370	$120,000	$172,370	$172,370

Most useful next

Formula

A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) − 1) / (r/n)]

• A = final balance
• P = initial principal
• PMT = periodic contribution
• r = annual rate, n = compounds per year, t = years

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Compound Interest Calculator

Harness the power of compounding. Project how savings and investments grow with regular contributions and compound interest, with a year-by-year breakdown of contributions vs. interest earned.

#compound interest#investment growth#savings#future value#interest calculator

Live calculate

Presets

Initial Investment

Regular Contribution

Contribution Frequency

MonthlyQuarterlyAnnual

Interest Rate

% / year

Years to Grow

years

Compounding Frequency

Live mode: results update as you type.

Future Balance

$302,370

after 20 years at 7.00% compounded monthly

Initial Investment: $10,000
Total Contributions: $120,000
Total Interest Earned: $172,370
Final Balance: $302,370
Growth Multiple: 2.33×
Interest Share of Balance: 57.0%

Balance composition

Initial$10,000
Contributions$120,000
Interest$172,370

Year-by-year growth

Year	Balance	Cumulative Contributions	Cumulative Interest	Interest This Path
Year 1	$16,955	$6,000	$955	$955
Year 2	$24,413	$12,000	$2,413	$2,413
Year 3	$32,411	$18,000	$4,411	$4,411
Year 4	$40,986	$24,000	$6,986	$6,986
Year 5	$50,182	$30,000	$10,182	$10,182
Year 6	$60,042	$36,000	$14,042	$14,042
Year 7	$70,614	$42,000	$18,614	$18,614
Year 8	$81,952	$48,000	$23,952	$23,952
Year 9	$94,108	$54,000	$30,108	$30,108
Year 10	$107,144	$60,000	$37,144	$37,144
Year 11	$121,122	$66,000	$45,122	$45,122
Year 12	$136,110	$72,000	$54,110	$54,110
Year 13	$152,182	$78,000	$64,182	$64,182
Year 14	$169,416	$84,000	$75,416	$75,416
Year 15	$187,895	$90,000	$87,895	$87,895
Year 16	$207,710	$96,000	$101,710	$101,710
Year 17	$228,958	$102,000	$116,958	$116,958
Year 18	$251,742	$108,000	$133,742	$133,742
Year 19	$276,173	$114,000	$152,173	$152,173
Year 20	$302,370	$120,000	$172,370	$172,370

Most useful next

Formula

A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) − 1) / (r/n)]

• A = final balance
• P = initial principal
• PMT = periodic contribution
• r = annual rate, n = compounds per year, t = years

FAQ

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