How Do Kids Change Your Coast FIRE Plan?
Kids can affect Coast FIRE in two different ways: family costs today can reduce how much you invest, while expenses that continue into retirement can increase what the portfolio needs to fund. Model both separately.
Your Coast FIRE + Family Plan
Enter family costs not in normal household budget (e.g. childcare, activities).
Family Cost Timeline & PhasesConfigure up to 3 custom family expense phases
Affects current cash flow but is not part of retirement spending.
Affects current cash flow but is not part of retirement spending.
Affects current cash flow but is not part of retirement spending.
Planning AssumptionsShared return, inflation, fee and SWR assumptions
Modeled Real Return: 3.69%/yr
Your Coast FIRE Position With Family Costs
Coast FIRE Target Today
Your current investments of $200,000 yield a position of -$406,374 Gap against your target of $606,374. Temporary child expenses do not increase this target.
Current Investments
$200,000
Gap / Surplus Today
-$406,374
Current Family Costs
$18,000/yr
Modeled Coast Date
Age 55
Coast FIRE Path With Family Costs
Tracks your portfolio growth under no new contributions vs planned contribution path against your target.
Which Family Costs Change the Coast FIRE Target?
Shows how each user-entered family cost phase is classified by timing.
| Cost Phase | Annual Amount | Ends At | Affects Contributions? | Overlaps Retirement? | Affects Target? |
|---|---|---|---|---|---|
| Childcare | $18,000/yr | Age 42 | Yes | No | No |
| School / Activities | $6,000/yr | Age 50 | Yes | No | No |
| Education Support | $12,000/yr | Age 58 | Yes | No | No |
What Changes When a Major Family Expense Ends?
Select an expense phase to model how redirecting freed cash shifts your retirement contributions and Coast FIRE date.
Keep Education Savings Separate From Coast FIRE Assets
A 529 plan is an education savings account with a different purpose from the retirement portfolio. Keep it separate by default so the same dollars are not counted toward both goals (Investor.gov / IRS Pub 970).
Will Education Spending Overlap Retirement?
Does Having Kids Change How Much One Parent Works?
Kids Do Not Create One Permanent Expense Number
Child-related expenses occur in phases. Childcare may end years before retirement, while education support may overlap an early retirement. The Coast calculation must distinguish temporary Coast-phase expenses from costs the retirement portfolio will actually fund.
Does a 529 Count Toward Coast FIRE?
529 plans are designed specifically for education expenses under IRS Publication 970 rules. Keep 529 savings and retirement investments separate by default. Monthly 529 contributions can affect current family cash flow, and if education spending overlaps retirement, model the expected funding gap during those specific years.
Do Not Turn Today's Kid Costs Into Permanent Retirement Spending
Daycare or other temporary family costs can reduce current investment capacity without necessarily increasing the household's retirement budget. Only carry a cost into retirement when the plan actually expects it to continue.
Questions About Coast FIRE With Kids
Answers to common questions about childcare, 529 plans, college overlap, and family budgeting.
Should daycare costs increase my Coast FIRE retirement-spending target?▼
Not automatically. If daycare ends before retirement, treat it as a current cash-flow expense that may affect contributions and the Coast date rather than permanent retirement spending.
Should my children's 529 balances count as Coast FIRE investments?▼
Keep education savings separate by default. A 529 is intended for education expenses, while Current Investments represents the portfolio modeled toward retirement spending.
Do monthly 529 contributions affect Coast FIRE even if the 529 balance does not count?▼
They can affect current cash flow. Money directed to education savings is money that is not simultaneously being contributed to the retirement portfolio, so contribution assumptions should reflect the actual plan.
What if I plan to retire before my children finish college?▼
Model the overlap explicitly. Estimate the family support expected during those years, subtract education funding already assigned to that goal, and model any remaining amount alongside retirement spending for only the overlapping period.
What happens to Coast FIRE when childcare ends?▼
The expense ending does not automatically change the Coast target. However, if some of the freed cash is redirected to retirement contributions, the projected portfolio and modeled Coast date can change.
How should I model costs for children we have not had yet?▼
Use a future family-cost phase rather than adding an assumed permanent amount to today's retirement spending. Enter only expenses and timing you want the scenario to test.
What if one parent reduces work because of childcare?▼
Model the resulting household take-home income and retirement contribution changes separately. If one parent stops working materially, the One-Income Household scenario can model the broader household transition.
Want to Start Without Family Cost Inputs?
Use the main Coast FIRE Calculator to model baseline investments and pure portfolio growth.
Verified Sources & Methodology
IRC Sec. 72(t)(2)(A)(v) Early Distribution Exception
2026 Federal Brackets & Standard Deductions
Summary Plan Description (SPD) Distribution Rules
Retirement Claiming Ages (62–70)