Understand what a SIP projection can and cannot show
A guide to contribution timing, step-up and inflation assumptions.
VertexFiles editorial · Updated 6 September 2026
A scenario is not a forecast
The assumed annual return is an input you choose, not a predicted market return. The model converts an effective annual growth assumption to a constant monthly growth rate. Real investment returns fluctuate and can be negative. A smooth upward table is a property of the chosen model, not evidence that an investment will behave that way.
Distinguish contributions from gains
The invested column combines the initial amount with all monthly deposits. The difference between the modeled value and those contributions is the illustrative gain or loss. Increasing the monthly deposit raises the invested amount as well as the possible final value, so compare both columns rather than focusing only on the total.
Check timing and annual increases
Beginning-of-month contributions receive that month's modeled growth; end-of-month contributions do not. An annual step-up increases the contribution after each block of 12 deposits. Keep the timing and step-up assumptions the same when comparing different growth rates.
Read the inflation adjustment carefully
The inflation-adjusted value expresses the modeled final balance in today's purchasing power using the chosen inflation assumption. It is not a tax-adjusted return or a guarantee of future spending power. Investment expenses, taxes, contribution interruptions and variable returns are excluded.