FIRE Number by Age: How Much You Need at Every Stage
Published June 2026 · 5 min read
Your FIRE number is a moving target — it changes with your age, spending, and time horizon. Here's exactly what you need at 30, 40, and 50, broken down by lifestyle.
FIRE Number at Age 30 (35-year runway to traditional retirement)
| Lifestyle | Annual Spend | FIRE @ 4% | Monthly Savings Needed* |
|---|---|---|---|
| Lean | $30K | $750K | $1,050 |
| Moderate | $50K | $1.25M | $2,150 |
| Comfortable | $75K | $1.875M | $3,600 |
| Fat | $100K | $2.5M | $5,100 |
FIRE Number at Age 40 (15-year runway)
| Lifestyle | Annual Spend | FIRE @ 3.5% | Monthly Savings Needed* |
|---|---|---|---|
| Lean | $30K | $857K | $2,900 |
| Moderate | $50K | $1.43M | $5,600 |
| Comfortable | $75K | $2.14M | $9,000 |
The Key Insight: Earlier = Easier Per Month
Starting at 30, the monthly savings needed is modest because compound growth does the heavy lifting over 25 years. Starting at 40, you need roughly 2x the monthly contributions because you have half the time. Age 50 is the hardest: most of your FIRE number must come from existing savings, not new contributions.
The takeaway: start early. Even $500/month at 25 compounds to over $1.2M by 55. Waiting until 40 means contributing $2,500/month for the same result. Use our FIRE Number Calculator to plug in your exact age, savings, and goals.