Required Lumpsum Calculator US
Find the one-time investment needed today to reach a future financial goal.
How it works
Compound interest earns returns on both your original money and the returns already added. Adding a regular monthly contribution accelerates growth further over time.
A = P(1 + r/n)^(nt) + contributions compounded monthly- Longer time horizons benefit most from compounding
- More frequent compounding gives slightly higher growth
- The donut shows how much of your final balance is interest vs money you put in.
Frequently asked questions
How much lump sum do I need to reach a goal?
Divide the future goal by (1 + return)^years. For $100,000 in 10 years at 8%, that is about $46,319 today.
What is present value?
The amount today that is equivalent to a future sum, given a rate of return. It is the lump sum that grows into your goal.
What return rate should I assume?
Use a realistic expected return for your investments, and remember returns are not guaranteed, so test a few rates.
Why does a longer horizon lower the required lump sum?
Because the money has more time to compound, so a smaller amount can grow into the same goal.
Does inflation affect this?
Yes. If your goal is in today’s dollars, build in inflation, since future purchasing power is lower than the nominal figure suggests.
Is this financial advice?
No. It is an educational estimate. For investment decisions, consult a qualified financial professional.
The lump sum you need to invest today
This calculator finds the single amount you would need to invest now to reach a future goal, given an expected return. It is a present-value calculation: PV = FV ÷ (1 + r)^t, where FV is the goal, r the annual return and t the years.
Worked example
To have $100,000 in 10 years at an 8% annual return, you would need to invest 100,000 ÷ 1.08^10 ≈ $46,319 today. The rest — over $53,000 — would come from compound growth on that lump sum.
What moves the number
A higher expected return or a longer time horizon both reduce the lump sum required, because compounding does more of the work. A shorter horizon or lower return means you must put in more upfront to hit the same target.
Returns are not guaranteed and inflation erodes future purchasing power, so treat the figure as a planning estimate. For decisions about investing toward a goal, consider speaking with a qualified financial professional.
Results are estimates for general guidance in United States and may not reflect the latest local rates, fees or rules. Check official sources before making decisions.