70% savings rate
= 8.3 years to FIRE
Save 70% of your take-home pay every year, invest it in a broad stock index, and you\u2019ll reach financial independence in roughly 8.3 years \u2014 regardless of how much money you make.
The shockingly simple part: your income doesn\u2019t matter.
Someone earning $40,000 and someone earning $400,000 both reach FIRE in the same time if they save 70% of their take-home pay. That\u2019s because your FIRE target (25x spending) scales with spending, and your savings scale with spending too. The ratio \u2014 and therefore the timeline \u2014 stays constant.
What if the market returns more or less than 7%?
Historical US stock market has averaged ~10% nominal / ~7% real. Internationally diversified portfolios typically land in 5\u20137%.
| Real annual return | Years to FIRE | Vs. baseline (7%) |
|---|---|---|
| 5% | 8.8 years | +0.5y |
| 6% | 8.5 years | +0.2y |
| 7%baseline | 8.3 years | — |
| 8% | 8.0 years | -0.2y |
| 9% | 7.8 years | -0.4y |
Change your savings rate
Even 5 percentage points shifts your timeline dramatically. Compare:
The math, explained
Let s be your savings rate, r be the real annual return, and w be your safe withdrawal rate (4% by default).
Your FIRE target is 1/w times your annual spending (25x at 4%). Your annual contribution is s/(1-s) times your annual spending. Set the future value of an annuity equal to the target and solve:
years = ln(1 + ((1-s)/s) \u00d7 (r/w)) / ln(1+r)
Plug in s = 0.70, r = 0.07, w = 0.04 and you get 8.3 years. The spending term cancels out, which is why the answer is income-invariant.
Frequently asked
Is a 70% savings rate realistic?+
70% is extreme — usually only feasible for high-income earners in low-cost-of-living areas, or tech/finance professionals with strong equity comp. Gets you to FIRE in 8.3 years.
Why doesn't income matter in this calculation?+
The math is income-invariant because both your savings AND your FIRE target scale linearly with spending. If you double your income but keep the same savings rate, you also double your spending, which doubles your FIRE target. The ratio stays the same, so the time to FIRE stays the same. This is the counterintuitive insight Mr. Money Mustache popularized in "The Shockingly Simple Math Behind Early Retirement."
What if the market returns less than 7%?+
The time to FIRE at 70% savings rate would be longer. See the sensitivity table on this page — at a 5% real return, it takes 8.8 years; at 9% it takes 7.8 years. 7% real is the historical US stock market average. Internationally or with more bonds, expect closer to 5–6%.
Should I count my mortgage as savings?+
Principal paydown on a primary home is net-worth-building, so some FIRE frameworks count it. But FIRE math typically assumes your target replaces your actual spending, which still includes housing costs. Simplest approach: only count contributions to investment accounts (brokerage, IRA, 401k, HSA) as "savings" in this calculation. Treat home equity as a separate asset.
Does this account for taxes?+
The 70% rate should be applied to your take-home (post-tax) pay, and your "spending" includes what you actually spend in retirement. The 4% safe withdrawal rate assumes you cover taxes from those withdrawals, so the math comes out right. Pre-tax 401(k) contributions effectively boost your savings rate since you're investing dollars that would otherwise go to taxes.
What\u2019s your real timeline?
The 70% savings rate is a shortcut. Take the 2-minute quiz to get a personalized timeline based on your actual income, assets, and target lifestyle \u2014 then save it and track progress over time.
Assumptions: 7% real return \u00b7 4% safe withdrawal rate \u00b7 today\u2019s dollars