RD vs SIP: The Real Comparison Most Websites Get Wrong

₹10,000/month for 20 years: a bank RD at 7% gives ₹52.44 lakh. An equity SIP at 12% CAGR gives ₹99.91 lakh — nearly double. But the real story is even more dramatic. After 30% tax on RD interest, you keep ₹43.91 lakh. After LTCG tax on SIP gains, you keep ₹90.58 lakh. And in today's purchasing power (adjusted for 6% inflation)? RD gives you ₹13.69 lakh of real value. SIP gives ₹28.24 lakh. The 20-year wealth gap is ₹46.67 lakh post-tax — all from the same ₹10,000/month contribution.

Most RD vs SIP comparisons stop at nominal returns. This guide goes three layers deeper: pre-tax, post-tax, and inflation-adjusted — because what matters isn't the number on paper but what that number can actually buy. We also show when RD genuinely wins over SIP (hint: it does, for short-term goals). SIP benefits from rupee cost averaging (buying more units when markets dip), while RD offers a fixed interest rate with zero volatility — each strength matters in the right context.

RD vs SIP: The Core Feature Comparison

The Numbers: ₹10,000/Month — Pre-Tax Comparison

All figures computed via month-by-month simulation (RD compounded quarterly at 7%, SIP at 12% CAGR):

At 3 years, SIP leads by just ₹31,000 — barely worth the market risk. At 20 years, SIP leads by ₹47.47 lakh — a transformational difference. The compounding gap widens exponentially with time, which is exactly why tenure matters more than the instrument itself. Use our Lumpsum Calculator to model one-time investments alongside regular contributions.

The Real Comparison: Post-Tax Returns (30% Bracket)

This is where RD falls apart. RD interest is taxed at your full slab rate, while equity SIP gains enjoy a flat 12.5% LTCG with ₹1.25 lakh annual exemption:

Notice the tax efficiency: at 10 years, SIP generates 2x the gains (₹11.23L vs ₹5.47L) but pays less absolute tax (₹1.25L vs ₹1.64L). This is because equity LTCG at 12.5% is far kinder than the 30% slab rate on RD interest. The same tax disadvantage applies to fixed deposits — any interest income taxed at slab rate is structurally inferior to equity taxation. When selecting SIP funds, also compare the expense ratio across AMCs — even a 0.5% difference compounds significantly over 15-20 years. For a complete financial planning framework covering how different instruments compare after tax and inflation, see our mutual fund real returns analysis and the CAGR vs absolute returns framework.

The Final Layer: Real Returns After Inflation

The metric that actually matters — what your money can buy in today's rupees after both tax and inflation erosion:

The RD real value column is devastating: after 20 years of disciplined ₹10,000/month saving, your money buys only ₹13.69 lakh worth of goods in today's prices — less than what you even invested in the early years. The RD didn't grow your wealth; inflation silently ate it. SIP preserves and doubles your purchasing power. For the underlying formula, see our real rate of return guide and the Rule of 72 for quick doubling-time estimates.

When RD Genuinely Wins Over SIP

RD isn't always the wrong choice. For short-term goals where capital safety matters, RD is superior because equity SIP carries downside risk:

For 1-2 year goals — a wedding, vacation, car down payment — RD guarantees your exact maturity amount. No equity SIP can promise that, no matter how good the fund. The rule: use RD for goals under 3 years, SIP for goals beyond 5 years, and evaluate risk tolerance for the 3-5 year grey zone.

The Smart Strategy: Use Both RD and SIP

Instead of choosing one, allocate based on goal timelines. Here's a practical framework for a person saving ₹30,000/month across multiple financial goals and investment horizons:

As short-term RD goals are met (vacation done, car bought), redirect that ₹8,000/month into SIP — this gradually shifts your allocation toward growth. For retirement planning, use our Retirement Corpus Calculator and FIRE Calculator. Generate retirement income via SWP strategy using our SWP Calculator. Compare all retirement instruments in our NPS vs PPF vs EPF guide. Check how your salary hike tracks inflation. For tax-efficient options under Section 80C, ELSS SIP gives both equity growth and tax deduction — something RD cannot offer. Understand the CPI index that measures your real inflation, and see the history of India's inflation to understand why fixed-rate instruments lag. Compare asset classes in our gold vs FD vs equity analysis and use our Step-Up SIP Calculator, PPF Calculator, EPF Calculator, EMI Calculator, Mutual Fund Calculator, and Purchasing Power Calculator to model any scenario.