Meet the author
Daniel Reed
Coast FIRE calculations & assumptions
Explore Coast FIRE formulas, return assumptions, withdrawal rates and how to interpret calculator results.
Background
About Daniel
The guides in this collection explain the numbers behind Coast FIRE: compound-growth formulas, consistent units, inflation-adjusted returns and sensitivity to assumptions. The focus is on transparent calculations, worked examples and understanding what a calculator result can tell you.
Areas of focus
Topics covered
- Compound-growth formulas
- Real and nominal returns
- Withdrawal-rate assumptions
- Calculator troubleshooting
Editorial standards
Clear sources. Visible assumptions.
These guides explain educational models and the assumptions behind their results. Read the site’s methodology and source register alongside each article’s examples and references.
Explore the library
Guides by Daniel
Coast FIRE Calculator Troubleshooting
Understand unexpected Coast FIRE results: unchanged targets, inflation, contributions, return assumptions, input errors and differences between calculators.
Read guide →calculationsCoast FIRE Formula Explained
Learn the Coast FIRE formula in simple terms. See what each number means, follow an easy example, and understand why age, return, inflation, and retirement spending change the result.
Read guide →scenariosCoast FIRE by Age
A Coast FIRE number changes with age because age changes how many years the existing portfolio has to compound toward the selected retirement target. Explore mathematical scenarios across different starting ages.
Read guide →strategyCommon Coast FIRE Mistakes
Most Coast FIRE errors come from one of two places: the calculation uses inconsistent inputs, or the result is interpreted as meaning more than the calculation actually shows.
Read guide →calculationsHow to Calculate Your Coast FIRE Number
Step-by-step guide to calculating your personal Coast FIRE number with real examples and adjustable assumptions.
Read guide →assumptionsWhat Return Rate Should a Coast FIRE Calculator Use?
There is no single return rate that is universally correct for a Coast FIRE calculator. Learn how return assumptions affect the calculation.
Read guide →assumptionsReal Return vs Nominal Return in Coast FIRE
Nominal return is investment growth before adjusting for inflation. Real return measures growth after accounting for inflation.
Read guide →assumptionsHow Withdrawal-Rate Assumptions Change Your Coast FIRE Number
A withdrawal-rate assumption changes a Coast FIRE calculation because it determines the modeled retirement portfolio target.
Read guide →