Multi-bucket · Inflation-aware · Step-up SIP

Goal-based SIP that doesn't lie with one flat number

Most SIP calculators assume 12% returns forever and forget inflation. Ours uses an age-based equity glide-path (100−age% equity, rest debt), inflates your goal correctly, and supports step-up SIP. The required monthly SIP comes out 30-50% higher than naive tools — i.e., realistic.

Glide-path · 100−age equity Equity · 12% · Debt · 7% Step-up · 10% / yr Cost · Free

Plan your goal

Tell us the goal corpus in today's rupees, your age (drives equity allocation) and inflation. We solve for the SIP needed.

Required monthly SIP
14,287

To reach inflation-adjusted target of ₹3.21 Cr in 20 years.

Future target
₹3,21,00,000
Today's ₹1 Cr inflated at 6% for 20 yr
Blended return
10.6%
68% equity (@12%) + 32% debt (@7%)
Equity vs Debt allocation
Equity · 68% Debt · 32%

Year-by-year corpus growth

01 — Logic

How the calculator actually solves for SIP

Step 1 — Inflate the target

A ₹1 Cr corpus today is not ₹1 Cr in 20 years. At 6% inflation, you actually need ₹3.21 Cr.

Inflated target target_future = target_today × (1 + inflation)years

Step 2 — Pick equity-debt mix from age

The classic rule: % equity = 100 − age. A 32-year-old gets 68% equity, 32% debt. Caps at 80% equity even for very young investors (avoid extreme concentration) and at 30% equity for 70+ (capital preservation).

Glide-path (default) equity_pct = clamp(100 − age, 30, 80) debt_pct = 100 − equity_pct

Step 3 — Blended return

Equity 12% pre-tax (Nifty 50 + diversified MF historic). Debt 7% pre-tax (corporate bond fund + PPF blend).

Blended return r = (equity_pct × 0.12) + (debt_pct × 0.07)

Step 4 — Solve for SIP

Without step-up (closed form):

Standard FV annuity, solve for p p = target_future / [ ((1+i)n − 1) / i × (1+i) ] where i = r/12 monthly, n = years × 12 months

With step-up (no closed form — binary search):

Step-up FV (numeric) fn maturityForInitial(p_init): bal = 0; p = p_init for year in 1..years: for month in 1..12: bal += p bal *= (1 + i) p *= 1.10 // 10% step-up annually return bal binary_search(p_init) until maturityForInitial(p_init) == target_future

Converges in ~25 iterations to ₹1 precision. Runs in milliseconds in your browser.

02 — Strategy

What separates this from a generic SIP calc

1. Inflation is non-negotiable

If your goal is "₹1 Cr for retirement at 60", you don't actually want ₹1 Cr — you want the purchasing power of ₹1 Cr today. At 6% inflation over 28 years, that's ₹5.1 Cr in nominal terms. Naive SIP calculators that ignore inflation underestimate the required SIP by 3-5x.

2. Goal-specific inflation

General CPI is ~5%, but for specific goals:

3. Age-based glide-path matters more than people think

A 30-year-old planning for 60 has 30 years to absorb equity drawdowns; the 2008-style 50%+ crash recovers in 3-5 years and they end up better off. A 55-year-old with 5 years to retirement cannot absorb that drawdown — a crash 1 year before retirement permanently impairs the corpus. The 100−age rule isn't optimal but is reasonable for retail. SEBI's RIA framework allows model portfolios within these bands.

4. Step-up changes everything

Salaries grow ~10% per year for the first 15 years of a career. A flat SIP of ₹30,000/mo means in year 10 you're still saving ₹30,000 from a ₹2L/mo salary — silly. Step-up SIP (₹30K → ₹33K → ₹36K…) is what real households actually do. Toggle it on and watch the required initial SIP drop 35-40%.

Insider tip: link your step-up to your appraisal cycle — instruct your AMC (or Coin / Groww) to bump SIP every April by 10%. Most platforms support this natively. Forgetting to step up is the #1 reason people miss long-term goals despite "doing SIP".

5. Re-allocate as you age

Don't run an 80%-equity SIP for 30 years. Every 5 years (or when age crosses a 5-year band: 30, 35, 40…), shift 5-10% from equity to debt funds via a SWP or rebalance. Locks in equity gains at the ₹1L LTCG exemption and protects against late-cycle crashes.

03 — Tax notes

Pre-tax vs after-tax — read this before SIPing

The 12% equity / 7% debt assumptions are pre-tax. After-tax effective returns:

If you're in the 30% slab and using debt MFs (not PPF/EPF) for the debt sleeve, lower the debt return assumption from 7% to 5% to stay realistic. The required SIP will jump ~10%.

04 — FAQ

Common questions about goal-based investing

Why use age-based equity allocation?

Equity returns higher (~12%) but with 30%+ drawdowns. Younger you are, longer your earning horizon, more drawdown you can absorb. The 100−age rule starts a 30-year-old at 70% equity and shifts toward debt as retirement nears.

What returns do you assume for equity and debt?

Equity: 12% pre-tax. Debt: 7% pre-tax. Blended return = (equity_pct × 0.12) + (debt_pct × 0.07).

How is step-up SIP solved?

Step-up has no closed-form FV. We binary-search for the initial SIP that hits target when grown 10% annually with monthly compounding. Converges in ~25 iterations to ₹1 precision.

Difference vs a regular SIP calculator?

Regular ones use flat 12% return, ignore inflation, give optimistic numbers. Ours: inflates target, age-aware blend (lower for older), step-up support. Required SIP comes out 30-50% higher — i.e. realistic.

Which goals does this work for?

Single-goal future expenses: retirement, child education, house down-payment. For multi-goal planning, run separately per goal and sum the SIPs.

Should I really put 70% in equity at age 30?

For long horizons (>10 years), yes. For short (<5 years), 70% equity is risky — a crash could derail. Override the slider for short-horizon goals.

Is 6% inflation right?

India CPI averages ~5% but goal-specific differs: education 8-10%, healthcare 9-12%, real estate 4-6%. 6% is general-purpose; adjust per goal.

Does this account for tax?

Returns shown are pre-tax. For 15+ year horizons tax shaves ~1% off effective return — bake it in by lowering equity to 11%.

Disclaimer. Returns shown are illustrative pre-tax assumptions (equity 12%, debt 7%) based on long-term historic Nifty 50 and Indian corporate bond fund data; actual returns will differ. Past performance is not indicative of future results. The age-based glide-path is a heuristic, not a personalized recommendation — your risk tolerance, income stability, and existing assets all matter. Consult a SEBI-registered investment advisor before committing significant capital. Pricing/rules as per Budget 2025; verify against final Finance Act.