Formula
Future value = starting amount × (1 + periodic rate)^periods + monthly contribution × (((1 + periodic rate)^months − 1) ÷ periodic rate). If the rate is 0, future value = starting amount + monthly contribution × months.
Investment Calculator
Project an investment balance from starting amount, monthly contributions, annual rate, time horizon and compounding frequency.
Worked example
For a 5,000 starting amount, 250 monthly deposits, 10 years and 6% annual interest compounded monthly, the monthly rate is 0.06 ÷ 12 and there are 120 months. The starting amount grows to about 9,096.98 and the deposits grow to about 44,637.45, giving a future value of about 53,734.43.
Professional note
Master’s Tip: always print a 0% scenario beside the entered-rate scenario. The gap between those two numbers shows how much of the plan depends on assumed growth rather than cash actually deposited.
Regional and unit assumptions
Standard or basis: transparent future-value arithmetic with nominal annual rate, user-entered compounding frequency and end-of-month deposits. It does not model tax, APR disclosures, pension rules, account fees or guaranteed investment performance.
Assumptions and limitations
- The annual rate is a user-entered planning rate, not a guaranteed return.
- Monthly contributions are treated as equal end-of-month deposits.
- The compounding frequency controls the starting amount growth factor; monthly deposits are accumulated monthly.
- Taxes, fees, inflation, changing rates, missed deposits and investment risk are not included.
- This is transparent finance arithmetic only, not financial advice.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Future value = starting amount × (1 + periodic rate)^periods + monthly contribution × (((1 + periodic rate)^months − 1) ÷ periodic rate). If the rate is 0, future value = starting amount + monthly contribution × months.
Standard or basis
Standard or basis: transparent future-value arithmetic with nominal annual rate, user-entered compounding frequency and end-of-month deposits. It does not model tax, APR disclosures, pension rules, account fees or guaranteed investment performance.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: always print a 0% scenario beside the entered-rate scenario. The gap between those two numbers shows how much of the plan depends on assumed growth rather than cash actually deposited.
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Questions
How do you calculate future value?
Compound the starting amount forward by the periodic rate, then add the accumulated value of regular deposits over the same time period.
Are monthly contributions made at the beginning or end of the month?
This calculator assumes contributions are made at the end of each month. Beginning-of-month deposits would have one extra month to grow.
What happens if the interest rate is 0?
The result becomes simple cash accumulation: starting amount plus monthly contribution multiplied by the number of months.
Is future value the same as compound interest?
Future value is the projected ending amount. Compound interest is one method used to grow the starting balance and deposits toward that amount.
Does this include inflation, tax or fees?
No. The calculator shows arithmetic growth from the entered assumptions only. Real accounts or investments may be affected by inflation, tax, fees and changing returns.
Calculation note
Future value arithmetic turns today’s money and planned deposits into a projected future amount. It is useful for savings plans, classroom finance, quote comparisons and investment examples, but the answer is only as reliable as the entered rate and deposit assumptions.
Future value projects forward from known inputs
The starting amount, contribution amount, rate, time and compounding basis are visible because each one can materially change the answer. The formula does not hide the fact that the future value is an estimate, not a promise.
Deposits need a timing convention
This page assumes monthly contributions arrive at the end of each month. That conservative convention keeps the report simple and prevents the calculator from quietly giving deposits extra growth time.
The 0% comparison keeps the projection honest
A zero-rate row shows the cash-only total. Comparing that row with the entered-rate result reveals how much projected growth is doing in the calculation.
Future value and present value are paired ideas
Future value moves money forward through time. Present value works backward from a future amount to an equivalent amount today. Using both pages together can make finance comparisons clearer.