How the FIRE calculator works

Last reviewed 11 Oct 2026. Review EPF / PPF / NPS rates each quarter (PPF is set quarterly). These pages are analytics from the numbers you enter, not a forecast or a recommendation of any scheme.

Conventions

Same money conventions as SIP v2: contributions on the 1st of the month, CAGR-true monthly rate i = (1+R)^(1/12)−1, monthly IRR.
A goal dated year Y happens on 1 April of Y (start of the Indian FY).
Starting withdrawal rate defaults to 3.33% (about 30×). Indian studies place the range around 3–3.5%.
NPS before 60: grow to 60, apply the PFRDA lump-sum rule, discount back at the post-FI return. The 20% annuity is not counted.
PPF monthly contributions are capped at ₹12,500.

Simple worked example (F0)

₹50,000/month today, 15 years, 6% inflation, 3.33% starting withdrawal rate → annual spending at FI ₹14,37,935 → FIRE number ₹4,31,81,229 (₹1,80,18,018 in today's money). Flat SIP at 12% ₹90,730/mo; 11% with a 5% step-up ₹75,378/mo to start. Coast number today at 11% ₹90,25,064.

Persona (F1)

Age 32, FI at 45, ₹60,000/mo core, health ₹36,000/year. Regular FIRE number ₹6,08,40,447 (core ₹4,61,17,368, health ₹59,73,359, goals after FI ₹87,49,721).

Limitations

Returns are deterministic except in the paid sequence replay.
Salary tax, home loans, emergency funds and insurance cover are not modelled.
Annuity income from NPS is stated and left out.
One post-FI return; goals are dated 1 April.
Drawdown tax uses the equity LTCG engine on the core pot. Bucket-wise EPF/PPF/debt tax is later.