Deposit timing
The same deposit total can follow different paths.
A deposit can only participate in modeled growth after it enters the balance. This calculator uses a simplified end-of-month schedule. It does not currently model payroll dates, biweekly deposits, employer match timing, or contribution pauses.
01 / FIELD NOTE
Month-end deposits in this tool
The model adds one equal contribution at the end of each month. A deposit made on the last day of a month does not earn the assumed return for that month. A beginning-of-month deposit would have one additional modeled month compared with a month-end deposit of the same amount.
02 / FIELD NOTE
Payroll schedules are not identical
A workplace plan may process deductions on pay dates and deposit them under its own procedures. Pay frequency, start date, changes, unpaid leave, payroll corrections, and plan administration can shift actual deposit dates. The calculator does not read a payroll calendar or verify when a plan posted contributions.
03 / FIELD NOTE
Compare schedules on an equal basis
If comparing deposit schedules outside this tool, specify the same total annual contribution, the exact dates, whether deposits are assumed to earn returns immediately, and whether the return convention is effective or nominal. Otherwise the comparison may reflect inconsistent assumptions rather than frequency alone.
04 / FIELD NOTE
Employer match has separate rules
A match may be calculated each payroll period, subject to a cap, and might or might not be reconciled later through a true-up. Eligibility, eligible compensation, vesting, and timing come from the plan documents. The calculator does not include matching deposits. Ask the plan administrator how a match is calculated for the specific plan.
05 / FIELD NOTE
Tax-year limits are separate from timing
Contribution limits apply under rules for a particular account and year; a schedule does not create additional annual room. For 2026, the IRS announced a $24,500 elective-deferral limit for many employer plans. Catch-up rules and plan terms can change the allowable amount. Confirm the correct limit and treatment with IRS guidance and the plan.