Annuity Payment Calculator: Estimate Periodic Income

An annuity payment calculator estimates the equal payment you would receive each period from a specified present value, interest rate, and payment term. Enter the amount invested, annual rate, and years; the calculator returns the periodic payment and the total paid over the term.

Formula

This calculator models an ordinary annuity: a series of equal payments made at the end of each month. It uses the standard fixed-payment formula:

Payment = PV × r / [1 − (1 + r)⁻ⁿ]

• PV is the present value, or amount used to fund the annuity, in dollars.
• r is the monthly interest rate as a decimal: annual rate in percent ÷ 1,200.
• n is the number of monthly payments: years × 12.
• Payment is the level monthly amount, rounded to the nearest cent.

Total of payments is the rounded monthly payment multiplied by the number of months. “Payments above present value” is that total minus the starting amount. It is a mathematical difference, not a guaranteed investment return or a measure of profit after inflation, fees, or taxes.

Worked Example

Using the calculator’s default inputs—$100,000 present value, 5% annual interest, and 10 years:

1. Convert the annual rate to a monthly decimal: 5 ÷ 1,200 = 0.0041666667.
2. Find the number of monthly payments: 10 × 12 = 120.
3. Substitute into the formula: $100,000 × 0.0041666667 ÷ [1 − (1.0041666667)⁻¹²⁰].
4. The monthly payment is approximately $1,060.66 after rounding to cents.
5. Total payments are $1,060.66 × 120 = $127,279.20. The difference above the starting value is $127,279.20 − $100,000 = $27,279.20.

Assumptions

• The interest rate remains fixed throughout the term.
• Payments are equal and made at the end of each month.
• Interest compounds monthly at the annual rate divided by 12.
• The calculation excludes contract charges, taxes, inflation, adjustments, and any payment guarantees or other features not entered here.

How to Use the Estimate

Enter the amount that will fund the payment stream, the annual interest assumption, and the number of years payments will continue. The result is a mathematical estimate for a level monthly stream. Use the annual rate specified for the particular scenario being evaluated; do not treat the example rate as a current quote or an offer.

The displayed total is the sum of the rounded monthly payments. Actual contract calculations can use unrounded amounts internally, different payment dates, or a rate convention that does not match this simplified monthly model. A small difference from a provider’s illustration may therefore reflect rounding or contract details rather than an arithmetic error.

Annuity products can differ substantially. Some payments may vary, start later, continue for a person’s lifetime, or include a beneficiary or refund feature. Those terms cannot be represented by this basic level-payment formula. Read the contract’s payment schedule and obtain its stated figures for an actual product.

When This Calculator Applies—and When It Does Not

The formula is suitable for estimating a fixed stream of equal payments from a starting balance when a fixed periodic rate and a fixed number of payments are assumed. It is also the same basic present-value relationship used in many fixed-payment financial calculations, although this page interprets the result as annuity income.

It does not calculate the payout for a lifetime-only arrangement, variable returns, inflation-linked payments, or payments that begin immediately. An immediate annuity often pays at the start of each period; that timing changes the result. A deferred annuity has an accumulation period before payments begin, which also needs separate modelling. The calculator should not be used to infer a product’s guaranteed value or to compare contracts without accounting for their specific terms.

Common Mistakes and Limits

• Mixing rate units: Enter an annual percentage such as 5, not 0.05. The formula converts the percentage to a monthly decimal.
• Entering months as years: The term field is in years. A 10-year term creates 120 monthly payments.
• Assuming “total” means interest earned: Total payments include repayment of the original present value. The difference shown is not adjusted for timing, inflation, expenses, or taxes.
• Ignoring payment timing: End-of-month payments are assumed. Beginning-of-month payments have a different present value relationship.
• Relying on rounded figures: The payment is rounded to cents, and the total uses that rounded amount. A contract may calculate and display figures under different rounding conventions.

The model also assumes that the stated annual rate can be represented by monthly compounding at one-twelfth of that rate. It does not account for changing rates, withdrawals, deposits during the payout period, or insurer-specific terms. Confirm the applicable rate, payment frequency, start date, and payment guarantees from the relevant contract documents.

Frequently Asked Questions

What is an annuity payment calculator?
It estimates equal periodic payments from a present value, assumed interest rate, and payment duration. This version calculates monthly payments made at the end of each month.

How is an annuity payment calculated?
Multiply the present value by the monthly rate, then divide by one minus one plus the monthly rate raised to the negative number of payments. The number of payments is the term in years multiplied by 12.

Does this calculator show a lifetime annuity payment?
No. It assumes a known number of monthly payments, not an unknown lifetime. Lifetime payout estimates require product-specific assumptions and terms that are not included here.

Why is the total paid higher than the amount entered?
With a positive assumed rate, the payment stream includes both the original present value and the effect of interest over time. The difference is not necessarily a net gain because it ignores inflation and any product costs or other conditions.

Can I use an annual payment schedule?
Not with this calculator as configured. It converts the annual rate into a monthly rate and calculates monthly payments. A different payment frequency requires a formula using that period’s rate and number of payments.

Is this a quote for an annuity contract?
No. It is estimate arithmetic for education, not financial advice. The result is an estimate, and the contract’s disclosure gives the exact figures.

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in pv | Present value | $ | 100000 | 1 | 100000000
in apr | Annual interest rate | % | 5 | 0.01 | 100
in yrs | Payment term | years | 10 | 0.0833 | 50
out pmt | Monthly payment | $ | round(pv * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2
out tot | Total of payments | $ | pmt * yrs * 12 | 2
out gain | Payments above present value | $ | tot - pv | 2