Coast FIRE lets people stop making retirement contributions once their portfolio hits a target "Coast FIRE number." The strategy works like this: you invest aggressively for a set period, then stop adding money and let compound growth do the rest.
Here's the appeal. If you're 35 with $500,000 saved and calculate that this amount will grow to $2 million by age 65 through market returns alone, you've hit your Coast FIRE number. You stop contributing entirely. Your money compounds for 30 years without another dollar from you. You're free to redirect cash toward other goals: a house down payment, starting a business, or simply enjoying more spending money now.
The math works because time compounds wealth. A $500,000 portfolio earning 7% annually grows to roughly $7.6 million in 30 years. Reaching Coast FIRE early means you've engineered financial flexibility years before full retirement.
But this strategy carries real tradeoffs. First, you need substantial savings upfront. Most people cannot accumulate $500,000 by 35. Second, Coast FIRE assumes you trust market returns. A major downturn early in your coasting period reshapes your retirement timeline. Third, inflation erodes purchasing power. Your Coast FIRE number should account for future cost of living, not today's prices.
Coast FIRE also works best for higher earners who hit the target young. A 45-year-old with $750,000 saved can coast to 65, but that 20-year window produces less growth than a 30-year window.
The strategy shines as a hybrid approach. You don't need to choose between traditional saving and full FIRE. Coast FIRE lets you max retirement accounts aggressively in your twenties and thirties, then pivot to other financial priorities while your existing nest egg grows.
Whether Coast