Step-Up SIP Calculator

Created by Arunangshu DasReviewed Nov 9, 2026

Project monthly contributions that rise every 12 payments by a fixed amount or percentage.

Compare the stepped plan with a flat baseline on the same return and payment timing.

Projected ending value

Enter a monthly plan or load the worked example.

Index 0 is the start of the first month. The final value is measured at the end of the last month. The model uses equal periods and a constant assumed return.

Understand what drives the projection

Walk through the increase schedule and separate additional deposits from additional investment growth.

Read the complete Step-Up SIP guide

Formula and methodology

Ending value = sum of each monthly contribution × its remaining monthly growth factor.

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).

Definitions

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.

Verified worked examples

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.

Interpretation

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.

Inputs and interpretation

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.

Assumptions and limitations

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.

Supported domain and common mistakes

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.

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.

Frequently asked questions

When does the first SIP increase apply?

The first 12 scheduled amounts use the starting contribution. The first increase applies to payment 13. A second applies to payment 25.

How do I choose fixed amount or percentage?

Choose fixed amount to add the same amount each year. Choose percentage to apply the same percentage to the previous monthly amount. Changing modes clears the increase input.

Can I enter a zero step-up?

Yes. Both projections then use the same schedule, so the ending-value difference and its contribution and growth components are zero.

How does a partial year work?

Only payments within the horizon are counted. At 13 months only one payment uses the first increase.

Can the extra modeled growth be negative?

Yes. Extra deposits can lose value when the assumed return is negative. They can still increase ending value compared with the flat plan.

Does the currency selector change my results?

It changes currency labels and number formatting. The projection uses the entered amounts in one currency throughout.

Sources and 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.

Reviewed 2026-11-09. AI-assisted content under operator editorial responsibility. No independent expert financial review is claimed.