How Much to Save?

Finding Your Required Savings Rate

This calculator answers a practical question: Given where I am now and where I want to be, how much do I need to save each month to get there?

It's the reverse of the other FIRE calculators. Instead of telling you when you'll retire, it tells you what monthly contribution will get you to your target by your chosen retirement age. It's the reality check that turns a vague goal into an actionable number.

The Three Inputs That Matter

Your required monthly savings depends on three things:

• Your current savings: The more you've already saved, the less you need to contribute going forward (compound growth does more of the work).
• Your target portfolio: A higher target means more monthly contributions needed.
• Your timeline: More years means smaller monthly contributions (you have more time for compound growth).

Change any of these, and your required savings changes. If the number feels too high, you have levers to adjust.

The Math Behind the Number

The calculator uses the future value formula to work backwards. Given a starting point, ending point, timeline, and expected return, it solves for the monthly contribution that bridges the gap.

Why Starting Early Matters So Much

The earlier you start, the smaller your monthly burden. Compound growth does the heavy lifting for early starters.

Let's say you want $1,000,000 by age 65 with 5% real returns and no current savings:

Starting at 25 vs. 45 means contributing less than a third per month—and $269,000 less total. Time is the most valuable asset in retirement planning.

The "Growth from Compound Interest" Percentage

The calculator shows what percentage of your final portfolio comes from investment growth vs. your contributions. The earlier you start, the higher this percentage—compound growth does more of the work.

If 70% of your final portfolio comes from growth, you're leveraging time effectively. If only 30% comes from growth, you're relying heavily on raw savings (which usually means you started late or have a short timeline).

What If the Number Feels Too High?

If the required monthly savings exceeds what you can afford, you have options. Don't give up—adjust.

Extend the Timeline

Working even 2-3 years longer can significantly reduce your monthly burden. The math is dramatic: each additional year of contributions and growth makes a big difference.

Reduce Your Target

Revisit your expenses. Can you realistically live on less in retirement? Every $100/month reduction in expected expenses cuts your target by $30,000 (25x rule). That might translate to $50-100 less per month in required savings.

Start Where You Can

If you can't save $1,500/month, save $500. Progress matters more than perfection. Increase your contributions with each raise. Automate increases so you don't have to think about it.

Automate and Forget

Set up automatic transfers the day after payday. Money you never see is money you don't miss. Most people who successfully reach FIRE say automation was the key—willpower is finite, but automatic transfers happen every month.

Where to Put Your Savings

The calculator tells you how much to save, but not where to put it. Here's the general priority:

1. Employer 401(k) Up to the Match

If your employer matches 50% up to 6% of your salary, that's an instant 50% return. There's no investment that beats free money. Always capture the full match before putting money anywhere else.

2. High-Interest Debt

If you have credit card debt at 18%, paying it off is a guaranteed 18% return. Pay off anything above 7-8% before investing beyond the employer match.

3. Roth IRA or Traditional IRA

Max out your IRA ($7,000/year in 2024, $8,000 if 50+). Roth is usually better for young people in lower tax brackets; Traditional is often better for high earners.

4. Max the 401(k)

Beyond the match, contribute more to your 401(k) up to the annual limit ($23,000 in 2024, $30,500 if 50+). This reduces your taxable income and grows tax-deferred.

5. Taxable Brokerage

If you've maxed tax-advantaged accounts, open a regular brokerage account. No tax benefits, but also no contribution limits or early withdrawal penalties.

What to Invest In

Keep it simple. Low-cost index funds (like total stock market or S&P 500 funds) are what most FIRE practitioners use. Look for expense ratios under 0.1%. Avoid actively managed funds, individual stock picking, and anything with high fees.

Building the Savings Habit

Knowing how much to save is easy. Actually doing it is hard. Here's how to make it stick.

Pay Yourself First

Treat savings like a bill. It's not optional spending money that happens to be left over—it's a non-negotiable expense that comes off the top. Budget everything else around it.

Automate Everything

Set up automatic transfers to happen right after payday. Your 401(k) contributions are already automated. Do the same for IRA contributions and brokerage transfers. If you have to manually move money each month, you'll eventually forget or talk yourself out of it.

Prevent Lifestyle Inflation

When you get a raise, increase your savings before increasing your spending. The easiest way: commit to saving 50% of every raise. You still get to enjoy some of the extra money, but your savings rate keeps climbing.

Celebrate Milestones

FIRE is a long journey. Celebrate when you hit $10,000 saved. Then $50,000. Then $100,000. Each milestone is proof that you're making progress. The early milestones feel slow; the later ones come faster thanks to compound growth.