How much do you need invested today so growth alone carries you to your retirement number? And at your pace, when can you stop saving?
Your Coast FIRE number today
$249,841
At your pace you can stop contributing at age 44, with $454k invested.
Retirement target
$1.25M
Progress to Coast
48%
Your portfolioCoast lineAge →
Ask about your result
An AI reads the numbers above and explains what they mean for you, in plain English. It only runs when you press the button.
0/400
Explainer: the coast line bends
The amount you need invested is smaller the younger you are, because every dollar has longer to compound. Drag the age and watch the Coast number fall as the years to retirement grow.
You'd need $471,112 invested at 45 to coast to $1.25M by 65. That is 38% of the target; the other 62% comes from 20 years of 5% real growth.
Rule of 72: at 5% real, money doubles roughly every 14.4 years.
How Coast FIRE is worked out
First the target: retirement spending divided by your withdrawal rate. Then the Coast number: that target discounted back to today at your real return over the years until retirement. If you have at least that much invested, you can stop adding money and still arrive on time, as long as returns cooperate. The "stop saving" age runs your current contributions forward until the balance crosses the coast line.
Coast FIRE pairs well with a lower-stress job: you only need to earn your current spending. To leave work entirely before retirement age, see the FIRE calculator; to keep some part-time income, try Barista FIRE.
Questions people ask
What is Coast FIRE?
Coast FIRE is the point where you have saved enough that, with no further contributions, investment growth alone will reach your full retirement number by your target retirement age. After that you only need to earn enough to cover current spending.
How do I calculate my Coast FIRE number?
Take your retirement target (yearly spending ÷ withdrawal rate) and discount it back to today at your real return: Coast number = target ÷ (1 + real return)^(years to retirement). With a $1.25M target, 30 years to go and a 5% real return, you need about $289,000 invested today.
What return should I use for Coast FIRE?
Use a real (after-inflation) return, because your target is in today's dollars. Historically a stock-heavy portfolio has returned around 5% to 7% after inflation over long periods. A cautious 4% to 5% gives a safer Coast number.
Is Coast FIRE risky?
It relies on decades of market growth that is not guaranteed, and stopping contributions removes your safety margin. Many people keep contributing a little, or aim for a Coast number with a buffer of 10% to 20%.