Methodology

Last verified: July 2026

Most calculators show nominal growth. RupeeReality shows what you keep after inflation and taxes.

Real returns

Every investment calculator computes two numbers: the nominal corpus, which is what the headline return compounds to, and the real value, which is that corpus expressed in today's purchasing power. Real value uses the inflation rate you set (default 6% p.a.) and applies it to the full holding period.

Tax treatment

Equity gains are taxed under Section 112A: LTCG at 12.5% plus 4% cess on gains above ₹1.25 lakh a year, STCG at 20% for holdings under 12 months. Interest from fixed deposits and recurring deposits is added to taxable income and taxed at your slab; TDS thresholds of ₹50,000 a year (₹1 lakh for senior citizens) apply. The income tax model uses the FY 2026-27 slabs for both regimes, the Section 87A rebate (nil tax up to ₹12 lakh taxable income in the new regime), and standard deductions of ₹75,000 (new regime) and ₹50,000 (old regime).

Small savings and EPF

PPF compounds at 7.1% p.a. with a ₹1.5 lakh yearly contribution cap. SSY pays 8.2% p.a. EPF pays 8.25% p.a. with 12% employee and 12% employer contributions. NPS calculations use the 40% annuity requirement and the ₹50,000 extra deduction under Section 80CCD(1B). Rates are set by the National Savings Institute and EPFO and are reviewed on a fixed schedule.

Salary estimates

The salary model converts CTC into estimated monthly take-home by subtracting income tax, employee EPF, and other payroll deductions. City salary context comes from MoSPI's PLFS mean monthly wages. Those benchmarks provide context only; they never feed an affordability calculation.

Formulas

The calculators use standard financial formulas: compound interest for lumpsums and FDs, annuity math for SIPs and step-ups, and amortization for loan EMIs. Stamp duty uses each state's registered rate plus local levies. All logic is deterministic and open, and every time-sensitive constant carries its source and last-verified date.

Verification and review

Tax rules are checked against the Income Tax Department after each Union Budget. NSI small-savings rates are reviewed quarterly. EPF is reviewed annually. Each constant lists its source and verification date on the Data Sources page.