Finance and Business
Coast FIRE Calculator
Coast FIRE Calculator estimate the invested balance needed today to grow into a retirement target without additional contributions.
Finance and Business
Coast FIRE Calculator
Estimate the invested balance needed today to grow into a retirement target without additional contributions.
Formula
Retirement target = annual spending / withdrawal rate; Coast FIRE balance now = target / (1 + return)^years.
About the Coast FIRE Calculator
Estimate the invested balance needed today to grow into a retirement target without additional contributions.
How the Coast FIRE Calculator Works
The spending target is capitalized with the entered withdrawal rate, discounted back from retirement age at the assumed annual return, and compared with current investments.
Formula
Retirement target = annual spending / withdrawal rate; Coast FIRE balance now = target / (1 + return)^years.
The calculation runs in your browser. Values are validated for required ranges, compatible units, and method-specific restrictions before results are displayed.
Required Inputs
- Current age (required).
- Retirement age (required).
- Annual retirement spending (required).
- Withdrawal rate (required) - enter in %.
- Expected annual return (required) - enter in %.
- Current invested balance (required).
Results Reported
The result panel reports the final answer and the intermediate quantities needed to check the calculation:
- Retirement portfolio target (currency)
- Coast FIRE balance needed today (currency)
- Current surplus or gap (currency)
- Current investments at retirement (currency)
- Years to retirement (years)
Coast FIRE Calculator Example
Select Example Data in the calculator to load this reproducible input set:
| Input | Example value |
|---|---|
| Current age | 35 |
| Retirement age | 65 |
| Annual retirement spending | 50000 |
| Withdrawal rate | 4 % |
| Expected annual return | 6 % |
| Current invested balance | 150000 |
How to Use the Calculator
- Confirm that the calculator title and formula match the quantity you need.
- Enter every required value using the unit shown with its field.
- Select Example Data to inspect a valid input set, or enter your own values and select Calculate.
- Review all reported values and the displayed formula before using the answer.
- Use Copy Result or Download CSV when you need a reusable record.
Accuracy and Limitations
Returns, inflation, taxes, fees, spending, and withdrawal sustainability are uncertain. Use real return with spending in today's money, or nominal return with future nominal spending.
Keep units consistent, use measurements that represent the actual situation, retain full precision during the calculation, and round only the final answer. Professional decisions may require current official rules, field measurements, laboratory methods, or specialist review.
Frequently Asked Questions
What does the Coast FIRE Calculator calculate?
Estimate the invested balance needed today to grow into a retirement target without additional contributions.
Which formula does the Coast FIRE Calculator use?
Retirement target = annual spending / withdrawal rate; Coast FIRE balance now = target / (1 + return)^years. The spending target is capitalized with the entered withdrawal rate, discounted back from retirement age at the assumed annual return, and compared with current investments.
What should I check before using the Coast FIRE Calculator result?
Returns, inflation, taxes, fees, spending, and withdrawal sustainability are uncertain. Use real return with spending in today's money, or nominal return with future nominal spending.