STP Calculator
Key takeaways
- Over 3 years, ₹9.00 L of the ₹10.00 L lumpsum moves across: the target fund ends at ₹10.88 L, the source still holds ₹2.08 L — ₹12.96 L in all.
- The waiting money earns too: the source fund adds ₹1.08 L of its own at 6% while the transfers run.
- With no transfers at all, the lumpsum sitting in the source fund at 6% would end at ₹11.97 L; the monthly shift into the 12% fund ends at ₹12.96 L — a difference of ₹99,372.
Yearly schedule
| Year | Source fund | Target fund | Moved | Total |
|---|---|---|---|---|
| 1 | ₹7.52 L | ₹3.20 L | ₹3.00 L | ₹10.72 L |
| 2 | ₹4.88 L | ₹6.81 L | ₹3.00 L | ₹11.69 L |
| 3 | ₹2.08 L | ₹10.88 L | ₹3.00 L | ₹12.96 L |
About the STP Calculator
A Systematic Transfer Plan (STP) moves a fixed amount out of one mutual fund every month and into another. The "source" is usually something low-volatility — a liquid or debt fund holding a lumpsum — and the "target" is usually equity. It is a way of putting a lumpsum into the market in instalments rather than all at once, while the portion not yet moved keeps earning the source fund's own return instead of sitting idle.
This calculator simulates the plan month by month rather than using a closed formula, because there is no closed form once the source is allowed to run out. Each month, in this order: that month's transfer is taken out of the source, capped at whatever is actually there so it can never overdraw; then each fund grows for the month at its own rate on what it now holds. Every rupee earns one fund's return for the month, never both. "Total portfolio value" is what both funds are worth together at the end, and it is simply "Target fund value" plus "Source balance left".
If the source cannot sustain the chosen monthly transfer for the whole period, it reaches zero before the period ends. Nothing more transfers after that, but the target fund keeps growing at its own rate through the months that remain, and the schedule note names the month the source emptied. "Total transferred" is then less than the monthly amount multiplied by the number of months chosen, because the final transfer was only whatever remained.
Both return rates are figures you enter, not rates any fund guarantees. Equity in particular swings well above and below its long-run average, so treat the projection as an illustration of the mechanism at the rates assumed.
Frequently asked questions
How is an STP calculated?
Month by month. The transfer leaves the source first; then the source grows by its monthly rate (annual rate ÷ 12 ÷ 100) on what is left, and the target grows on a balance that already includes this month's transfer. That ordering matters: each transfer earns a full month of the target's return, the same convention the SIP calculator uses for its own instalment, and stops earning the source's return the moment it moves — growing the source first would count a month of interest twice on every rupee moved.
What happens if the source fund runs out before the period ends?
The last transfer is whatever is left rather than the full monthly amount, the source closes at exactly zero, and nothing more transfers. The target fund keeps growing at its own rate until the end of the period, so the figures are a projection of the whole period, and the schedule note says which month the source emptied.
Is an STP the same thing as a SIP?
No. A SIP invests fresh money from your income every month. An STP moves money you already hold from one fund to another, so nothing new is added — the total across both funds only changes because of the returns each one earns. The SIP calculator on this site models the first case.
Why does the chart not stack up the way the SIP chart does?
Because the two columns here are balances, not flows. Each bar stacks that year-end's source balance and target balance, so its height is the whole portfolio at that moment. A cumulative chart would add the same rupees to themselves once per year. The SIP chart accumulates because its columns are money going in, which really does add up.
How is an STP taxed?
Each monthly transfer is a redemption from the source fund and a fresh purchase in the target, so every transfer can create a capital gain in the source. As of FY 2026-27, gains on debt mutual funds bought since April 2023 are taxed at your slab rate regardless of holding period, and equity gains depend on how long each transferred unit is then held in the target. This calculator does not model tax at all — see the Capital Gains Tax Calculator for that.
Are the returns shown here guaranteed?
No. Both rates are assumptions you type in. Liquid and debt funds fluctuate less than equity but are not fixed-return products either, and no mutual fund guarantees a rate. The result shows what the mechanism produces at the rates entered, nothing more.
Disclaimer: This calculator is for information and education only. It is not investment advice and not a recommendation to buy, sell or hold any investment. Where a rate of return, inflation or growth is an input, it is an assumption: actual returns vary and are not guaranteed, and past performance may or may not be sustained in future. It does not take your personal circumstances into account. Mutual fund investments are subject to market risks; read all scheme-related documents carefully. Every figure is computed solely by applying the formula and assumptions stated on this page to the inputs you entered.