MTMasterTool

Compound Interest Calculator

Calculate compound interest from your own entered figures.

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Currency: Amounts are calculated in the currency you select; this site does not convert between currencies and does not use live exchange rates.

What this tool does

Calculate compound interest from your own entered figures. Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Contributions are made at year-end.

How to use the Compound Interest Calculator

  1. Enter or select starting balance.
  2. Enter or select annual contribution.
  3. Enter or select annual return (%).
  4. Enter or select years to project.
  5. Enter or select stop contributions after year (0 = immediately).
  6. Read the calculated result; change any measurement to compare alternatives.

Formula

each year: balance=balance×(1+return/100)+(year<=coast?annual contribution:0)
balance
Starting balance
annual
Annual contribution
return
Annual return (%)
years
Years to project
coast
Stop contributions after year (0 = immediately)

Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Contributions are made at year-end.

Worked example

For compound interest calculator, the following measurements illustrate the exact method: Starting balance: 10000; Annual contribution: 6000; Annual return (%): 6; Years to project: 30; Stop contributions after year (0 = immediately): 20.

Inputs

  • Starting balance10000
  • Annual contribution6000
  • Annual return (%)6
  • Years to project30
  • Stop contributions after year (0 = immediately)20

Result

  • Ending balance$452,699.26
  • Total contributions$130,000.00
  • Investment growth$322,699.26

Results explained

Ending balance
Ending balance from the formula above. Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Contributions are made at year-end.
Total contributions
Total contributions from the formula above. Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Contributions are made at year-end.
Investment growth
Investment growth from the formula above. Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Contributions are made at year-end.

Frequently asked questions

each year: balance=balance×(1+return/100)+(year<=coast?annual contribution:0)

Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Contributions are made at year-end.

No. All numbers are entered by you or come from the dated reference table shown on this page; calculations run locally.

This is an estimate, not financial, tax or legal advice. Verify the inputs and output with official sources and a qualified professional.

Check period consistency, currency, percentage inputs and the assumptions: Constant assumed return, no live market prices, taxes, inflation or investment fees unless included in your inputs. Contributions are made at year-end.