Calculator Assumptions
v1.1 — June 2026Our calculators use default values based on official sources. These assumptions are versioned — when data changes, we update them and document why.
| Parameter | Default Value | Source & Rationale |
|---|---|---|
| Equity Returns | 12% p.a. | Long-term Nifty 50 history supports a high-single/low-double digit planning range; 12% remains a rounded planning default, not a guarantee. [NSE] |
| Debt Returns | 7% p.a. | Blended planning estimate anchored to current small-savings rates: PPF 7.1%, NSC 7.7%, 5-year time deposit 7.5%. [DEA] |
| Inflation Rate | 6% p.a. | RBI's CPI inflation-targeting framework is 4% with a 2% tolerance band; upper band used for conservative planning. [RBI/BIS] |
| PPF Interest | 7.1% p.a. | Ministry of Finance small-savings notification for Q1 FY 2026-27; rates unchanged from Q4 FY 2025-26. [DEA] |
| LTCG Tax (Equity) | 12.5% | Above ₹1.25 lakh annual exemption for specified equity LTCG. [IT Dept] |
| STCG Tax (Equity) | 20% | For applicable listed equity/equity fund transfers on or after 23 July 2024. [IT Dept] |
| EPF Interest | 8.25% p.a. | CBT, EPF recommended 8.25% for FY 2025-26; credit follows Government notification. [PIB] |
🧠 Why We Version Assumptions
Financial models are not truths — they're tools. When tax laws change (every Budget) or market conditions shift (every cycle), the "right" defaults change too. By versioning our assumptions, we teach a critical lesson: models evolve, and so should your understanding of them.
v1.1 — June 2026 (Official source refresh)
- PPF Rate: Kept at 7.1% after DEA Q1 FY 2026-27 notification confirmed small-savings rates remain unchanged.
- EPF Rate: Kept at 8.25% and updated source wording to FY 2025-26 CBT, EPF recommendation.
- Tax Rates: Reconfirmed equity LTCG 12.5% above ₹1.25L exemption and STCG 20% from Income Tax Department guidance.
- New Tax Regime: Synced internal config to AY 2026-27 slabs.
- Source Freshness: Updated policy-source dates and machine-readable formula/API metadata to June 2026.
v1.0 — January 2026 (Initial Release)
- Equity Returns: Set to 12% based on Nifty 50 20-year CAGR (~12.7%)
- Inflation: Set to 6% (RBI upper target band) for conservative projections
- LTCG Tax: Updated to 12.5% above ₹1.25L (Union Budget 2024-25)
- STCG Tax: Updated to 20% (Union Budget 2024-25)
- PPF Rate: 7.1% as per Q4 FY25 notification
- EPF Rate: 8.25% as per EPFO FY23-24 declaration
Future Updates
When official rates change or new budget announcements are made, we'll update this page with a new version entry documenting exactly what changed and why.
💡 How to Use This Information
- Our defaults are starting points, not gospel. Adjust them based on your situation.
- For conservative planning, use lower equity returns (8-10%) and higher inflation (7%).
- For aggressive scenarios, you might use higher returns — but understand the risk.
- Always re-run scenarios when major policy changes occur (Budget, RBI announcements).