What is SWP (Systematic Withdrawal Plan) & How to Calculate It?

Why this matters: A Systematic Withdrawal Plan (SWP) is a structured way to withdraw money periodically from an investment corpus — commonly used by retirees or investors who want regular income while keeping the remainder invested. Calculating the right SWP amount helps you avoid depleting your corpus too quickly while maintaining a steady cash flow.

Quick link: Open SWP Calculator

SWP — Basic concept

With an SWP you withdraw a fixed amount at regular intervals (monthly/quarterly/annual) from your investment account. The corpus continues to earn returns on the remaining balance. The goal is to choose a withdrawal amount that lasts for your desired number of years given an expected rate of return.

Core formula — fixed periodic withdrawal

To compute a fixed periodic withdrawal (withdrawal amount W) that fully depletes a corpus C in n periods when the periodic return is r, use the annuity / mortgage-style formula:

W = C × r
    ----------------------------
    1 − (1 + r)^−n
      

Where:

• C = Corpus (initial lump sum)
• r = periodic rate (e.g., monthly rate = annual_rate / 12)
• n = total number of periods (months = years × 12 for monthly withdrawals)

Worked example — Monthly SWP from ₹10,00,000 for 10 years at 8% p.a.

Assumptions: Corpus C = ₹10,00,000. Annual expected return = 8% → monthly r = 8% / 12 = 0.08 / 12 = 0.006666666666666667. Period = 10 years → n = 10 × 12 = 120 months.

Step-by-step calculation (digit-by-digit):

Step 1: Compute periodic rate r:
  r = 0.08 / 12 = 0.006666666666666667

Step 2: Compute (1 + r)^(-n):
  1 + r = 1 + 0.006666666666666667 = 1.0066666666666667
  (1 + r)^n = (1.0066666666666667)^120 ≈ 2.219640234544711
  (1 + r)^(-n) = 1 ÷ 2.219640234544711 ≈ 0.45052346071079324

Step 3: Denominator = 1 − (1 + r)^(-n) = 1 − 0.45052346071079324 = 0.5494765392892068

Step 4: Numerator = C × r = 1,000,000 × 0.006666666666666667 = 6,666.666666666667

Step 5: W = Numerator ÷ Denominator
  W = 6,666.666666666667 ÷ 0.5494765392892068 ≈ 12,132.759435535776

Result: Monthly SWP ≈ ₹12,132.76 (rounded).
      

Interpretation: withdrawing ~₹12,132.76 each month for 120 months will exhaust the ₹10 lakh corpus assuming a constant 8% p.a. return compounded monthly.

Worked example — Annual SWP from ₹10,00,000 for 10 years at 8% p.a.

If you prefer annual withdrawals, use the same formula with annual rate and n = years.

Assumptions:
  C = ₹10,00,000
  Annual rate R = 0.08
  n = 10 years

Step 1: Numerator = C × R = 1,000,000 × 0.08 = 80,000

Step 2: Compute (1 + R)^(-n):
  (1 + R)^n = (1.08)^10 ≈ 2.158924997272788
  (1 + R)^(-n) = 1 ÷ 2.158924997272788 ≈ 0.4631934880846842

Step 3: Denominator = 1 − 0.4631934880846842 = 0.5368065119153158

Step 4: W = 80,000 ÷ 0.5368065119153158 ≈ 149,029.48869707534

Result: Annual SWP ≈ ₹149,029.49 (rounded).
      

Inflation-adjusted SWP (growing withdrawals)

If you want your withdrawal to grow each year at an assumed inflation rate g, the first-year withdrawal W₀ that will grow at g and deplete corpus C in n years (with portfolio nominal return r) is:

W₀ = C × (r − g)
     -------------------------
     1 − ((1 + g) / (1 + r))^n
      

This is the growing-annuity formula (withdrawal increases at rate g each year).

Worked example — inflation-adjusted SWP

Assumptions: Corpus C = ₹10,00,000; Nominal return r = 8% = 0.08; Desired annual growth of withdrawals g = 5% = 0.05; n = 20 years.

Step 1: (1 + g) / (1 + r) = 1.05 ÷ 1.08 ≈ 0.9722222222222222

Step 2: ((1 + g) / (1 + r))^n = 0.9722222222222222 ^ 20 ≈ 0.5692602663480327

Step 3: Numerator = C × (r − g) = 1,000,000 × (0.08 − 0.05) = 1,000,000 × 0.03 = 30,000

Step 4: Denominator = 1 − 0.5692602663480327 = 0.4307397336519673

Step 5: W₀ = 30,000 ÷ 0.4307397336519673 ≈ 69,647.6262954642

Result: First-year withdrawal ≈ ₹69,647.63, then increase this amount by 5% each subsequent year.
      

Note: inflation-adjusted SWP preserves purchasing power; the initial withdrawal is lower than a fixed-withdrawal SWP because it grows over time.

Comparison table — SWP variants at a glance

Variant	Main idea	When to use	Pros	Cons
Fixed periodic SWP	Withdraw a constant amount every period until corpus runs out	When you need predictable cashflow (same amount)	Simple, predictable	Does not adjust for inflation (purchasing power falls)
Inflation-adjusted (growing) SWP	Withdraw an amount that grows at rate g each period	When you want to preserve purchasing power	Maintains real spending power over time	Initial withdrawal lower; sensitive to r−g
Bucket / laddered SWP	Use short-term liquid bucket for near-term needs & invest rest for growth	When risk-averse & want liquidity plus growth	Reduces sequence-of-returns risk	More complex to manage

Practical considerations & tips

• Assumptions matter: SWP depends heavily on assumed return (r) and compounding frequency. Test multiple scenarios.
• Sequence-of-returns risk: Early poor returns reduce sustainability — consider bucket strategies or a conservative glide path early on.
• Tax & withdrawals: Check tax implications of selling investments to fund SWP (capital gains, dividends).
• Adjust periodically: Revisit SWP amounts every 1–2 years as returns, inflation, or needs change.

Try our SWP Calculator

Use our interactive tool to input your corpus, expected returns, withdrawal frequency and years — it will compute fixed and inflation-adjusted SWP amounts and show depletion timelines:

Open SWP Calculator

Frequently asked questions

Disclaimer: Examples use assumed constant returns and rounded numbers for clarity. Real returns vary; consult a certified financial planner for personalised SWP planning.