Our Mathematical Methodology
eCalcy is built on the principle of "Open Logic." We don't believe in black-box calculations. Every number on our platform is derived from verifiable financial formulas and primary regulatory benchmarks.
01. The Core Engines
SIP & Wealth Compounding
Our SIP engine uses the standard Future Value (FV) formula of an Ordinary Annuity, adjusted for monthly compounding frequency:
*Where M is maturity, P is monthly investment, i is monthly interest rate, and n is number of months.
Loan Amortization (EMI)
EMI calculations are based on the reducing balance method, cross-verified against official bank amortization schedules:
02. Regulatory Alignment
We review our tax and interest benchmarks against applicable official rules so our calculators reflect current legislation.
Repo-rate linked EMI benchmarks and FD compounding rules.
Income Tax Act rules for FY 2025-26 (AY 2026-27) slabs, standard deductions, and 80C/80D logic.
Federal tax bracket inflation adjustments and standard deductions.
Historical mutual fund return benchmarks for realistic scenario planning.
03. Scenario Probabilities
Financial planning is rarely linear. Our planning tools add useful scenario layers to the core formulas:
Inflation Sensitivity: We allow users to adjust for the purchasing power of their future corpus.
Step-Up Capability: Modeling annual salary increments to reflect career progression.
Tax-Adjusted Returns: Calculating net post-tax maturity values based on LTCG/STCG rules.
Accuracy Disclosure
While our math is reviewed against applicable official rules and industry formulas, calculations are based on user inputs. Market-linked returns (SIP/Lumpsum) are never guaranteed. eCalcy is an educational planning aid and not a financial advisory service. Always verify critical figures with a licensed professional before committing capital.