Enter your current details and monthly contribution to estimate your total assets at retirement.
Retirement projection is built on compounding: returns earn returns, so the growth curve gets steeper the longer it runs. This tool splits your future balance into two parts and adds them together. Your current savings grow via Balance × (1+r)^n. Your recurring monthly contributions grow via the future-value-of-an-annuity formula: Monthly amount × [((1+r)^n − 1) / r], where r is the monthly return rate (annual rate ÷ 12 ÷ 100) and n is the total number of months (retirement age − current age, times 12). This is essentially the mortgage amortization formula run in reverse: a loan is "borrow now, repay in installments later," while retirement saving is "deposit a bit now, let time compound it into a lot."
Two mistakes are extremely common. First, people intuitively think in linear terms — "saving for 30 years vs. 15 years should give roughly double the result" — but compounding is exponential, so the real gap is usually far larger than double, because every additional year grows not just new contributions but the entire accumulated balance. Second, people underestimate the cost of starting late: contributing 10,000/month at a 5% annual return starting at age 30 until 65 (35 years) accumulates roughly 11,360,000 from contributions alone; starting the same 10,000/month plan at age 40 instead (25 years) only reaches about 5,960,000 — starting 10 years later cuts the final balance almost in half. That's compounding's extreme sensitivity to time, made concrete.
Monthly rate: r = 5 ÷ 100 ÷ 12 ≈ 0.004167. Total months: n = (65−30) × 12 = 420. (1+r)^420 ≈ 5.73. Future value of the current 200,000: 200,000 × 5.73 ≈ 1,147,000. Future value of the monthly 10,000 contributions: 10,000 × [(5.73 − 1) / 0.004167] ≈ 10,000 × 1,136 ≈ 11,360,000. Adding both together, the estimated total at retirement is about 12,510,000. Total contributions (200,000 current savings + 10,000 × 420 months = 4,200,000) add up to 4,400,000 — meaning roughly 8,110,000, or about 65% of the final balance, came purely from investment growth. That's the payoff of starting contributions early.
This tool assumes a constant annual return compounded monthly every single year — a simplification made to keep the math tractable. Real investment returns fluctuate year to year, sometimes well above and sometimes well below your long-run average. The tool also does not subtract inflation: if your return is 5% but inflation runs at 2% long-term, your real purchasing-power growth rate is closer to 3%, meaning the money you have in 35 years will buy less than the nominal figure suggests. Treat this tool as a way to compare strategies (e.g. saving 8,000/month vs. 12,000/month) rather than as precise retirement financial planning.
No. It calculates a nominal future value — the raw compounded number — without subtracting inflation. To approximate real purchasing power, you can enter "expected return minus expected inflation" in the return field instead, e.g. enter 3% if you expect a 5% return and 2% inflation.
The tool clamps years-to-retirement at 0 (using Math.max to prevent a negative value). With zero years, there's no time for compounding, so the projected total simply equals your current savings — monthly contributions aren't counted because there's no remaining time to accumulate them.
At 0%, the compounding formula is skipped (to avoid a division by zero) and the tool falls back to simple addition: total = current savings + monthly contribution × number of months. That's a pure-savings scenario with no investment growth at all, and the result is mathematically exact.
This tool doesn't tell you what's realistic — that depends entirely on your actual asset allocation. As rough reference points: bank savings deposits run about 1–2%, a balanced stock/bond portfolio roughly 4–6%, and a long-term all-equity index strategy roughly 6–8% (with higher volatility). Try several different rates to compare optimistic and conservative scenarios rather than relying on one single number.
No. Every calculation runs locally in your browser using JavaScript — there's no fetch call or server connection involved. The age, savings, and contribution amounts you enter exist only on this page and disappear the moment you reload it; nothing is logged or uploaded.