Step-Up SIP Formula and Annual Top-Up Examples

Separate the deposit increase from investment growth

Two plans can start at the same monthly amount and finish with different balances because one has more contributions. Compare the extra cash with the additional gain or loss before attributing the difference to compounding.

What is a step-up SIP?

A step-up SIP increases a monthly systematic investment after each block of 12 scheduled payments. The increase can be a fixed currency amount or a percentage of the previous monthly amount.

A step-up or top-up changes what you contribute. The effective annual return is a separate assumption about how the invested balance grows or shrinks.

Check the final commitment

A rising plan can suit a scenario where your available contributions increase over time. Read the final monthly payment alongside the ending balance, and compare the commitment across several possible increases.

Step-up SIP formula

For payment j starting at 1, completed blocks b = floor((j − 1) ÷ 12). The contribution is C + b × increment for a fixed increase or C × (1 + increase)^b for a percentage expressed as a decimal. Grow each contribution for the remaining periods using the monthly factor (1 + effective annual return)^(1/12).

FV = Σ Cⱼ × (1 + A)^((n − kⱼ) / 12)

Follow the first increase in month 13

At 500 monthly and a 10% increase, a 13-month plan contributes 12 × 500 + 550 = 6,550. At zero return the ending value is 6,550. The flat plan ends at 6,500, so the 50 difference is entirely extra principal.

At 25 months, the percentage plan moves from 500 to 550 to 605. A fixed increase of 50 gives 500, 550 and 600. This difference arises from the contribution schedule even at zero return.

1. Enter 500, a 10% increase, 0% annual return and 13 months.
2. Check that the first increased payment and last payment are both 550.
3. Switch to 12 months to see the increase disappear, then try 25 months to see the second increase.

Reconcile the ending-value difference

Additional contributions plus additional modeled gain or loss reconcile to the ending-value difference. At a negative return, the additional growth component can be negative while the stepped ending value remains higher than the flat value.

Compare the extra contributions to the ending-value difference. If extra cash was exposed to a negative rate, the difference in balances will be smaller than the extra cash. With a final end-of-month payment, that payment has no time to gain or lose value.

Choose the increase basis before entry

Enter the starting monthly amount, effective annual return and whole months. Choose an increase basis, enter an explicit zero for no increase, and choose when payments occur. Compare the final payment and the three components of the flat-plan comparison.

For a fixed yearly top-up enter an amount in the same major currency unit as the starting payment. For percentage top-up enter 10 for a 10% increase. Contribution timing changes when growth starts for each payment.

Compare flat, fixed-increase and percentage plans

Use the flat SIP calculator for a constant monthly plan. Use the Future Value Calculator when you need a starting balance and a constant periodic payment. The built-in flat comparison isolates schedule changes on matched assumptions.

Count blocks of 12 scheduled payments

The first increased payment is payment 13. Beginning payments use checkpoints 0 through n−1 and end payments 1 through n. The valuation is at n. Zero duration has an empty schedule. A zero payment does not count as a contribution.

The twelve-payment blocks are relative to the model start. They are independent of a calendar year, provider billing and leap days.

Respect the model bounds

Enter 0 to 1,200 months, amounts up to 10^12 for the starting contribution and fixed increase, and a percentage increase from 0 to 100%. Enter an effective annual return above −100% and up to 100%. The model uses up to 12 input decimal places and 80 significant digits, rejecting principal or ending values above 10^30.

A zero starting amount stays zero under percentage increases. With a fixed increase, the first positive payment can occur at installment 13. Display rounding can change a displayed reconciliation by a cent.

Keep rate and increase conventions separate

Match the same starting contribution, duration, timing and annual effective return before comparing. A fixed increase adds the same amount each year. A percentage applies to the previous monthly contribution and compounds across blocks.

An effective annual assumption of 12% converts to about 0.948879% monthly. Using 1% per month instead implies about 12.68% annual growth.

Use one currency throughout

For India, enter rupees and look for the SIP or top-up terminology. In the USA and Canada, monthly investment contributions describe the same schedule. In the UK use pounds for regular investing examples. In Australia use Australian dollars. The currency selector only formats the results.

Educational scope

Educational scenario in one currency. It excludes dates, provider rounding and rules, taxes, fees, inflation, FX and investment execution. Actual returns vary. This is not personalized investment advice.

Frequently asked questions

Sources and review

Sources reviewed Nov 9, 2026. Consult current local rules before relying on time-sensitive information.

• Zerodha step-up SIP calculator
• HDFC Mutual Fund top-up calculator
• Groww annual increase example
• Investor.gov monthly contributions
• Canada investor education
• MoneyHelper investing overview
• ASIC Moneysmart calculator