Savings Rate Fire Calculator

Savings Rate & FIRE Calculator

Your FIRE Trajectory

Savings Rate 0%

FIRE Number $0

Years to Financial Independence 0 Years

function calculateFIRE() { var income = parseFloat(document.getElementById('annualIncome').value); var expenses = parseFloat(document.getElementById('annualExpenses').value); var currentNetWorth = parseFloat(document.getElementById('currentSavings').value); var returns = parseFloat(document.getElementById('investmentReturn').value) / 100; var swr = parseFloat(document.getElementById('swr').value) / 100; if (isNaN(income) || isNaN(expenses) || income <= 0 || expenses < 0) { alert("Please enter valid positive numbers for income and expenses."); return; } var annualSavings = income – expenses; var savingsRate = (annualSavings / income) * 100; var fireNumber = expenses / swr; document.getElementById('resSavingsRate').innerText = savingsRate.toFixed(2) + "%"; document.getElementById('resFireNumber').innerText = "$" + fireNumber.toLocaleString(undefined, {maximumFractionDigits: 0}); if (annualSavings <= 0 && currentNetWorth = fireNumber) { document.getElementById('resYearsToFire').innerText = "Already FIRE!"; } else { // Formula: n = ln((FireNum * r + Savings) / (CurrentNW * r + Savings)) / ln(1 + r) // If returns are 0, use simple division var years; if (returns === 0) { years = (fireNumber – currentNetWorth) / annualSavings; } else { var numerator = (fireNumber * returns) + annualSavings; var denominator = (currentNetWorth * returns) + annualSavings; years = Math.log(numerator / denominator) / Math.log(1 + returns); } document.getElementById('resYearsToFire').innerText = years.toFixed(1) + " Years"; } document.getElementById('fireResults').style.display = 'block'; }

Understanding Your Savings Rate and FIRE Number

Financial Independence, Retire Early (FIRE) is a movement focused on extreme saving and investing to allow individuals to retire far earlier than traditional budgets suggest. The two most critical levers in this journey are your Savings Rate and your FIRE Number.

What is the Savings Rate?

Your savings rate is the percentage of your take-home pay that remains after all expenses are paid. Mathematically, it is: (Net Income - Expenses) / Net Income. While the average person saves 5-10%, those in the FIRE community often aim for 50% or higher. A higher savings rate does two things: it increases the amount of money you have to invest, and it decreases the amount of money you need to live on in retirement.

The 4% Rule and Your FIRE Number

The "FIRE Number" is the total amount of invested assets you need to cover your annual expenses indefinitely. This is typically based on the "4% Rule," which suggests you can safely withdraw 4% of your portfolio's value each year (adjusted for inflation) without running out of money. To calculate your FIRE number, multiply your annual expenses by 25 (the inverse of 4%).

Realistic Example

• Annual Income: $80,000 (after tax)
• Annual Expenses: $40,000
• Savings Rate: 50%
• FIRE Number: $1,000,000 ($40,000 × 25)
• Outcome: With $0 starting net worth and 7% market returns, you would reach FIRE in approximately 14.4 years.

How to Accelerate Your FIRE Date

To reduce the "Years to FIRE," you have three primary variables to control:

• Decrease Expenses: This has a double impact. It increases your monthly savings and simultaneously lowers your target FIRE number.
• Increase Income: Boosting your earnings while maintaining your current lifestyle (avoiding "lifestyle creep") allows 100% of new income to go toward investments.
• Optimize Investment Returns: While you can't control the market, minimizing fees through low-cost index funds and ensuring an appropriate asset allocation helps maximize growth.

Safe Withdrawal Rate (SWR) Considerations

The standard SWR is 4%, but many early retirees choose a more conservative 3.25% or 3.5% to account for longer retirement horizons (50+ years). Adjusting the SWR in the calculator above will show you how much more you might need to save to feel secure against market volatility.