Best Free Retirement Calculators USA 2026 -- 401k, Roth IRA & FIRE

Retirement planning in America comes down to three numbers: how much you're saving, how long you're saving it, and what tax treatment your account gets. Getting even one of these wrong by 1% can mean hundreds of thousands of dollars at retirement.

Here are the calculators every American needs in 2026 -- and the numbers behind them.

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2026 IRS Retirement Contribution Limits

|---------|----------|---------|-------|

| 401k (employee) | $23,500 | $31,000 | +$7,500 catch-up |

| Traditional/Roth IRA | $7,000 | $8,000 | +$1,000 catch-up |

| SIMPLE IRA | $16,500 | $20,000 | -- |

| SEP IRA | $70,000 | $70,000 | 25% of compensation |

| HSA (individual) | $4,300 | $5,050 | +$750 catch-up |

*Source: IRS.gov 2026 retirement plan contribution limits*

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The 5 Retirement Calculators Every American Needs

1. 401k Calculator with Employer Match

The most powerful feature most calculators skip: employer match. This is literally free money -- and the average American leaves $4,100/year unclaimed (Vanguard 2025 data).

Common match formulas:

"100% of first 3%" -> Contribute 3%, employer adds 3% free
"50% of first 6%" -> Contribute 6%, employer adds 3% free
"100% of first 4%" -> Contribute 4%, employer adds 4% free

Example: $80,000 salary, "100% match on first 4%"

Your contribution (4%): $3,200/year
Employer match: $3,200/year FREE
Over 30 years at 7%: $3,200/year x 2 = $643,000 total ($321,000 from free match)

[Try our 401k Calculator ->](/calculators/finance/401k-calculator)

2. Roth IRA Calculator (2026 Income Limits)

2026 Roth IRA income phase-outs:

Single filers: Phases out $150,000-$165,000
Married filing jointly: Phases out $236,000-$246,000
Over limit? Consider Backdoor Roth IRA conversion

The Roth IRA advantage: every dollar grows tax-free, forever. On $7,000/year for 30 years at 7%: your $210,000 in contributions becomes $756,000 -- and you pay zero tax on the $546,000 gain.

[Try our Roth IRA Calculator ->](/calculators/finance/roth-ira-calculator)

3. Roth IRA vs Traditional IRA Calculator

The choice depends on one variable: will you be in a higher or lower tax bracket in retirement?

| Choose Roth if... | Choose Traditional if... |

|-------------------|--------------------------|

| You're early in your career (lower bracket now) | You're in your peak earning years |

| You expect tax rates to rise | You expect tax rates to fall |

| You want tax-free income in retirement | You need the tax deduction now |

| You want no RMDs at 73 | State taxes will be lower in retirement |

[Try Roth vs Traditional Calculator ->](/calculators/finance/roth-ira-vs-traditional-ira-calculator)

4. FIRE Calculator (Financial Independence, Retire Early)

The 4% rule (Bengen 1994, Trinity Study): withdraw 4% of your portfolio in year 1, adjust for inflation each year, and have 95%+ probability of not running out of money over 30 years.

Your FIRE number = Annual expenses x 25

| Annual Spending | FIRE Number | Monthly savings at 7% to reach in 20 years |

|----------------|-------------|---------------------------------------------|

| $40,000 | $1,000,000 | $2,439/month |

| $60,000 | $1,500,000 | $3,659/month |

| $80,000 | $2,000,000 | $4,878/month |

| $100,000 | $2,500,000 | $6,098/month |

[Try our FIRE Calculator ->](/calculators/finance/fire-calculator)

5. Retirement Savings Gap Calculator

Fidelity age benchmarks (based on retiring at 67):

| Age | Savings Target | On $80k salary |

|-----|----------------|----------------|

| 30 | 1x salary | $80,000 |

| 40 | 3x salary | $240,000 |

| 50 | 6x salary | $480,000 |

| 60 | 8x salary | $640,000 |

| 67 | 10x salary | $800,000 |

[Try our Retirement Calculator ->](/calculators/finance/retirement-calculator)

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The Compound Growth Formula Behind Every Retirement Calculator

~~~

FV = PV(1+r)^n + PMT x [((1+r)^n - 1) / r]

~~~

Where: FV = future value, PV = current balance, r = periodic return rate, n = periods, PMT = regular contribution.

At 7% annual return, $500/month for 30 years starting from $0: $606,438

At 7%, $1,000/month for 30 years: $1,212,876

The rate matters less than the consistency. Starting at 25 vs 35 at $500/month at 7% means $606,438 vs $284,607 at 65 -- a $321,831 difference from 10 extra years.

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Frequently Asked Questions

How much should I have saved for retirement at 40?

Fidelity recommends 3x your annual salary by 40. On $80,000 salary: $240,000 target. Use our retirement calculator to see your exact gap.

What is the 4% rule?

The 4% rule states you can withdraw 4% of your retirement portfolio in year 1, then adjust for inflation each year, and have a 95%+ probability the money lasts 30+ years (Bengen 1994). FIRE number = annual expenses / 0.04 = expenses x 25.

Should I contribute to 401k or Roth IRA first?

Always get the full employer match first (100% return). Then max Roth IRA ($7,000) if income eligible. Then return to max 401k ($23,500). This is the optimal order for most Americans.

All calculators are free, no signup, 2026 IRS limits built in:

[401k Calculator](/calculators/finance/401k-calculator)
[Roth IRA Calculator](/calculators/finance/roth-ira-calculator)
[FIRE Calculator](/calculators/finance/fire-calculator)