Lumpsum Calculator

How does a lumpsum grow?

A lumpsum investment puts a single amount to work on day one and then leaves it untouched to compound. Because nothing is added later, all the heavy lifting is done by time and the rate of return — each year’s growth is calculated on the previous year’s larger balance, so the curve steepens the longer you stay invested.

That compounding is what separates a lumpsum from simple interest. Earn 12% on ₹1,00,000 and the first year adds ₹12,000; but by year ten the same 12% is applied to a balance above ₹2,50,000, so a single year now adds more than twice your original gain. The maturity value follows the classic compound-growth formula.

₹1 lakh, ₹5 lakh and ₹10 lakh at 12%

At an assumed 12% a year for 10 years, every rupee invested becomes roughly ₹3.11 — so the maturity value simply scales with how much you start with. The gain outstrips the original amount well before the ten years are up, which is compounding doing its work.

Lumpsum vs SIP

A lumpsum and a SIP answer two different questions. A lumpsum suits money you already hold — an inheritance, a bonus, maturity proceeds — and compounds the full amount from the start. A SIP suits money you earn month by month, spreading each instalment across market ups and downs.

Invest the same total either way and the lumpsum usually finishes ahead, purely because more money compounds for longer. But it also carries timing risk: commit everything just before a market fall and you feel the whole drop at once. If you hold a large sum but worry about the entry point, staggering it over a few months is a common middle path.

Why starting early matters

The biggest lever on a lumpsum is not the amount or even the return — it is how early you invest. Because compounding accelerates over time, the final years contribute the most growth, so the years you skip at the beginning are the most expensive ones to lose.

Take ₹1,00,000 at 12%. Left for 10 years it becomes about ₹3.11 lakh; give it 15 years — the same money invested just five years earlier — and it grows to roughly ₹5.47 lakh. Those five extra years add more than ₹2,00,000 without you contributing a single rupee more.