How to Calculate Retirement Income From Multiple Sources

Table of Contents

• Step 1: List Every Income Source and Its Tax Treatment
• Step 2: Estimate Each Source's Monthly and Annual Income
  • Social Security: Claiming Age Drives the Number
  • Pensions: Read the Statement, Not the Summary
  • Annuities: Split Qualified From Non-Qualified
  • Investment Accounts: Pick a Withdrawal Rate You Can Defend
  • Rental and Other Income
  • Then Do the Math
• Step 3: Calculate Your Combined Monthly Retirement Income
  • Worked Example: The Hendersons' Three Income Streams
  • Worked Example: A Single Filer With a Pension and IRA
• Use a Retirement Income Calculator or Build Your Own Worksheet
  • What to Look For in a Calculator
  • Building a Retirement Income Worksheet
• How Long Will My Retirement Savings Last?
  • A Simple Longevity Worksheet
  • Worked Example: $600,000 at $30,000 a Year
  • Sequence-of-Returns Risk and Longevity
  • Inflation-Adjusted Income and Purchasing Power
  • Social Security Coordination and the Survivor Math
  • Healthcare and Long-Term Care: The Costs Calculators Skip
• Account for Taxes, Inflation, and Irregular Expenses
• Compare Projected Income With Your Retirement Budget
• Conclusion: Turn Your Calculation Into a Plan
• Frequently Asked Questions

Last Updated: October 4, 2026

Step 1: List Every Income Source and Its Tax Treatment

Most people guess at their retirement income. Then they wonder why the number feels wrong. Building a real estimate of retirement income starts with a simple inventory, not a spreadsheet formula.

Retirement income is the total money you receive after you stop working, drawn from sources like Social Security, pensions, annuities, and personal savings. Each source arrives with its own tax rules, and those rules change what you actually keep.

Here is how the main sources stack up:

Write down every account, every benefit statement, and every pension letter. Do not skip small ones. A forgotten old 401(k) from a former job is one of the most common surprises.

Step 2: Estimate Each Source's Monthly and Annual Income

Next, convert every source into a monthly number. This is where how to calculate monthly retirement income gets concrete. Most calculator pages stop at "enter your balance and withdrawal rate." The step they skip is the one that matters: each source converts to income differently, and lumping them together hides errors.

Social Security: Claiming Age Drives the Number

Log into your my Social Security account and pull your benefit estimate at 62, at your full retirement age (FRA), and at 70. The Social Security Administration's benefit estimator shows those figures side by side.

The spread is not small. Claiming at 62 permanently reduces your benefit; waiting to 70 permanently increases it.

If you are married, coordinate with your spouse.

Pensions: Read the Statement, Not the Summary

Use the monthly amount printed on your plan statement. Two traps:

• Lump sum vs. annuity. If you took a lump sum, treat it like an investment account and apply a withdrawal rate, do not also count it as a monthly pension.
• Survivor election. A joint-and-survivor option lowers your monthly check but keeps income flowing to your spouse. A single-life option pays more now and stops at death. Pick the number that matches the election you actually made.

Annuities: Split Qualified From Non-Qualified

A qualified annuity (funded with pre-tax dollars, often inside an IRA) is taxed as ordinary income on every payment. A non-qualified annuity (funded with after-tax dollars) is taxed only on the earnings portion, using an exclusion ratio. If you have not annuitized, treat the contract value like an investment account instead.

Investment Accounts: Pick a Withdrawal Rate You Can Defend

For taxable brokerage, traditional IRA/401(k), and Roth accounts, you need a withdrawal rate. Many planners start with 4% a year, then adjust for risk tolerance and time horizon. On a $500,000 portfolio, 4% is roughly $20,000 a year, or about $1,667 a month.

But the rate is a starting point, not a rule. A few practical anchors:

• A 3% rate is more conservative and stretches the portfolio further.
• A 5% rate funds more spending now but raises the odds of running short.
• The rate should be applied to the balance you expect at retirement, not today's balance, if you are still contributing.

Rental and Other Income

Rental income is usually counted at net, rent minus mortgage, taxes, insurance, maintenance, and vacancy allowance. A property that grosses $2,000 a month may net $900 after a realistic vacancy and repair reserve. Do not count gross rent; it will overstate your income every time.

Then Do the Math

• Annual income = monthly amount x 12
• Monthly income = annual amount / 12
• Total = add every source together

Build the estimate source by source in a spreadsheet before you total anything. When a number looks wrong later, you can trace it back to one row instead of redoing the whole calculation.

Estimate each source on its own before you combine them. Errors hide in the mix, not in the individual numbers.

Step 3: Calculate Your Combined Monthly Retirement Income

Add your monthly figures from Step 2. The total is your projected retirement income, before taxes.

Keep taxes separate at this stage. Mixing gross and after-tax numbers is the single biggest mistake in retirement math. It makes a shaky plan look solid.

Worked Example: The Hendersons' Three Income Streams

The Hendersons have three sources:

• Social Security: $3,200/month combined
• Pension: $1,100/month
• IRA withdrawals: $1,800/month

Combined monthly income: $6,100. Annual: $73,200.

Now subtract estimated taxes. If roughly 15% goes to federal and state tax, they keep about $5,185 a month. That is the number their retirement budget must fit.

Worked Example: A Single Filer With a Pension and IRA

A single filer draws:

• Pension: $2,000/month
• IRA withdrawal: $1,500/month
• Social Security: $2,200/month

Combined: $5,700/month, or $68,400/year. After an estimated 18% tax hit, about $4,674 lands each month.

Two households, two very different tax pictures. Same math.

Use a Retirement Income Calculator or Build Your Own Worksheet

A retirement income calculator speeds up the math, but a retirement income worksheet forces you to understand it. We suggest both.

What to Look For in a Calculator

Good calculators share a few traits:

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• Separate fields for each income source
• A tax estimate, not just gross totals
• An inflation adjustment

The Consumer Financial Protection Bureau's retirement planning tools offers free starting points.

Building a Retirement Income Worksheet

Build your own in a spreadsheet with these columns:

• Source name
• Gross monthly amount
• Tax treatment

Add a total row. Update it once a year. That single habit does more for your plan than any app.

How Long Will My Retirement Savings Last?

This is the question behind every other question. The answer depends on three inputs: your savings balance, your withdrawal rate, and your time horizon. Most calculator pages give you a single number. A transparent worksheet gives you a range you can actually plan around.

A Simple Longevity Worksheet

Build four columns in a spreadsheet:

• Year (1 through 30, or however long you want to model)
• Starting balance
• Withdrawal (your annual draw, adjusted for inflation)

Run it three times: once with a 0% real return, once with a 3% real return, and once with a 5% real return. "Real" means after inflation, so the numbers stay in today's dollars and you are not fooled by nominal growth.

Worked Example: $600,000 at $30,000 a Year

A $600,000 portfolio drawn at $30,000 a year (a 5% rate) lasts about 20 years with no growth. Add a 3% real return and it stretches meaningfully further. Add a bad market in the first three years and it shrinks faster than the straight-line math suggests. That is the whole point of modeling a range instead of a single answer.

Sequence-of-Returns Risk and Longevity

Sequence-of-returns risk is the danger of a market drop right when you start portfolio withdrawals.

Longevity risk is the flip side: living longer than your money. A plan built to age 85 can fail at 92. The fix is not a higher withdrawal rate, it is a plan that flexes.

Withdrawing a fixed dollar amount from a falling portfolio is the fastest way to shorten its life. Consider a flexible withdrawal rule instead, for example, skip the inflation raise after a down year, or cap withdrawals at a percentage of the current balance.

Inflation-Adjusted Income and Purchasing Power

A dollar today does not buy what it will buy in 20 years. If you want $6,000 a month in today's dollars at retirement, and you are 15 years out, you need to inflate that figure, even modest inflation compounds. The same applies to income: a pension with no cost-of-living adjustment loses purchasing power every year.

Social Security Coordination and the Survivor Math

Claiming age does not just change your monthly check, it changes how long your portfolio has to carry the load. Every year you delay Social Security is a year your portfolio funds more of your spending, but it is also a year your eventual benefit is permanently higher and inflation-adjusted.

Healthcare and Long-Term Care: The Costs Calculators Skip

Medicare premiums, supplemental coverage, and out-of-pocket costs rise with age and are not fully captured by a generic inflation rate. Long-term care is the bigger wildcard: a stretch of care can run into the tens of thousands a year, and many families plan for it in advance rather than hoping it never happens. The Centers for Medicare & Medicaid Services publishes current Medicare cost information worth checking before you set your healthcare line.

A single "how long will it last" number is a guess. A worksheet with three return scenarios, an inflation adjustment, and a healthcare reserve is a plan.

Account for Taxes, Inflation, and Irregular Expenses

Taxes and inflation quietly reshape every projection. So do the expenses that show up once, not monthly.

• Inflation: $6,000 a month today buys less in 20 years. Adjust your figures upward each year.
• Taxes: Traditional accounts are taxed on withdrawal. Roth accounts are not. Plan the order you draw from each.
• Healthcare: Medicare premiums and out-of-pocket costs rise with age. Budget for them separately.

The Centers for Medicare & Medicaid Services publishes current Medicare cost information worth checking before you set your healthcare line.

Compare Projected Income With Your Retirement Budget

Now put the two numbers side by side: what you project and what you plan to spend.

If projected after-tax income tops your retirement budget, you have room. If it falls short, you have an income gap.

Review the gap every year. Small changes early beat big ones late.

Conclusion: Turn Your Calculation Into a Plan

Running the numbers is the easy part. Sticking to a plan when markets wobble is where most people struggle. At New Insight Financial, we help clients turn a rough estimate into a working retirement plan built around their own risk tolerance and timing. We offer income planning, Medicare navigation, and complimentary access to the Generational Vault® for secure storage of your financial and legal documents.