Deposits have their own clock
Payment frequency describes when new money arrives. Compounding frequency describes how a nominal annual rate becomes growth. A monthly contribution can be valued with an annually compounded rate by converting the annual growth factor to an equivalent monthly factor. Dividing every annual rate by 12 would confuse nominal and effective conventions.
Beginning versus end of period
At a 1% periodic rate, twelve end-period deposits of $100 accumulate to $1,268.25. Moving the same twelve deposits to the beginning produces $1,280.93 because each payment receives one extra period of growth. The larger result comes from timing, not from a different contribution total.
Increasing deposits and partial terms
An annual increase applies after each completed year, starting with the next scheduled payment. A 5% increase changes a $100 monthly contribution to $105 in year two. The model includes deposits only for complete payment periods. A remaining partial period earns growth on the existing balance but receives no extra deposit, even with beginning timing.
Read the reconciliation
Closing balance equals starting principal plus total deposits plus gross growth, less any modeled deductions. At zero interest, $1,000 plus twelve deposits of $100 ends at $2,200. The schedule makes it possible to check how much of a future savings balance comes from new money and how much comes from the assumed return.
Questions about this calculation
How can I check the inputs behind the result?
Open “Show calculation & assumptions” for the formula and timing conventions, then inspect the breakdown. Export CSV to keep the last calculated inputs and numerical results together.
Does this include taxes or changing market returns?
No tax calculation or variable market-return path is included. The task-specific assumptions above describe the scope. Calculated values are conditional on the inputs, not personalized recommendations.
Learn more
Start with the step-by-step future value formula guide.
Open the formula guide →How to calculate future value · Spreadsheet calculations · All learning guides
Use these figures to explore assumptions. Actual interest, returns, fees, taxes and purchasing power can differ.