Maturity Value Calculator - Compound Growth Forecast

A maturity value is the amount an investment or deposit is expected to be worth at the end of a stated term. Banks, credit unions, and brokerage platforms quote it for certificates of deposit, savings accounts, and planned contribution programs. The maturity value calculator compounds a starting principal at the stated annual rate and, when you add recurring deposits, also grows those contributions over the same horizon. The core compound-interest formula is MV = P × (1 + r/n)^(n t), where P is principal, r is the annual interest rate as a decimal, n is the number of compounding periods per year, and t is time in years. Monthly compounding uses n = 12, quarterly uses n = 4, and daily uses n = 365 in this calculator. If the time unit is months, the calculator converts the period to years by dividing by 12 before applying the exponent. Optional contributions use the ordinary-annuity accumulation formula. If PMT is the amount deposited each contribution period and m is the number of contributions per year, the contribution future value is PMT × [((1 + r/m)^(m t) − 1) / (r/m)] when the rate is positive. When the annual rate is zero, contributions simply add as PMT × m × t. Total contributions equal the original principal plus every deposit. Interest earned is maturity value minus total contributions. Those identities match common textbook treatments of compound growth, but they still omit important real-world details. Quoted APY already embeds compounding, so entering an APY as if it were a nominal APR can slightly overstate growth if you also choose a high compounding frequency. Taxes, early-withdrawal penalties, promotional teaser rates, and changing contribution amounts are outside the model. Contribution timing is treated as end-of-period, which is a reasonable planning convention rather than a bank ledger. Use the calculator to compare a lump-sum deposit with a savings habit, to see how daily versus annual compounding changes a multi-year CD, or to test a lower rate if the current offer is not guaranteed for the full term. Keep units consistent: a 4.5 percent rate is entered as 4.5, not 0.045. Review the interest-earned line as a sanity check; if it is negative, an input is usually inconsistent. Confirm actual account terms, compounding conventions, and tax treatment with the institution before relying on a figure for a contract or tax filing.