Portfolio Value Change Calculator: Percentage Change in Your Portfolio
Work out the percentage change in your investment portfolio between two values — and the dollar gain or loss — the basic return measure for a stock, fund, or whole-portfolio snapshot.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Portfolio change | Gain / loss |
|---|---|---|
| $50k to $58k (+16%) | 16.00% | 8,000 |
| $100k to $85k (−15%, down year) | -15.00% | -15,000 |
| $25k to $30k (+20%) | 20.00% | 5,000 |
| $200k to $210k (+5%) | 5.00% | 10,000 |
How This Calculator Works
Enter your portfolio value at the start and end of the period. The calculator finds the percentage change and the dollar gain or loss. Important: this simple change is only accurate if you didn't add or withdraw money during the period — contributions and withdrawals distort it.
The Formula
Percentage Change
Old is the starting value, New is the ending value
Worked Example
A portfolio rising from $50,000 to $58,000 is a 16% gain — $8,000. This works cleanly for a buy-and-hold period with no cash flows. But if you contributed $5,000 during the period, the simple change overstates your investment return (some of the rise is your own deposit, not growth), and a withdrawal understates it. With cash flows, you need a money-weighted (IRR) or time-weighted return to measure performance accurately — the simple percentage change only tells the true story when nothing went in or out.
Key Insight
Percentage change is the right tool for a clean before-and-after snapshot, but the single biggest mistake investors make in measuring returns is ignoring contributions and withdrawals. If you regularly add to a portfolio, a large 'gain' in raw value is mostly your own deposits, not investment performance — your account can grow while your investments underperform. Two proper measures handle this: time-weighted return (which strips out the effect of cash flows and is how funds report performance, ideal for judging the investments themselves) and money-weighted return / IRR (which accounts for the timing and size of your contributions, ideal for judging your actual experience). For a simple buy-and-hold position with no cash flows, the percentage change here equals the return. A few other notes: this is a nominal, before-fee, before-tax figure — inflation, fees, and taxes reduce the real return; and a single-period change tells you little about a volatile asset, so annualize multi-year changes (use a CAGR) and judge performance over meaningful periods rather than reacting to short-term swings. Use this calculator for clean snapshots and gain/loss figures; reach for time-weighted or money-weighted returns once contributions and withdrawals are involved.
Frequently Asked Questions
How is the portfolio value change calculated?
Subtract the starting value from the ending value, divide by the starting value, and multiply by 100. From $50,000 to $58,000 is ($58,000 − $50,000) / $50,000 = 16%, an $8,000 gain.
Does this work if I added or withdrew money?
No — not accurately. The simple change assumes no cash flows. If you contributed during the period, part of the rise is your deposit, not investment growth, so the percentage overstates your return; a withdrawal understates it. With cash flows, use a money-weighted (IRR) or time-weighted return.
What's the difference between time-weighted and money-weighted return?
Time-weighted return strips out the effect of contributions and withdrawals, measuring the investments' performance (how funds report). Money-weighted return (IRR) accounts for the timing and size of your cash flows, measuring your actual experience. Use time-weighted to judge the investments, money-weighted to judge your outcome.
Is this my real return?
It's a nominal, before-fee, before-tax figure. Inflation erodes real purchasing power, and fees and taxes reduce what you keep. For real return, subtract inflation; for after-tax/after-fee return, account for those too. The simple change is a starting point, not the full picture.
How should I judge a multi-year change?
Annualize it with a compound annual growth rate (CAGR) rather than using the raw total change, so you can compare it to other investments on a yearly basis. And judge performance over meaningful periods — a single-period change tells you little about a volatile portfolio.
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Methodology & Review
The change is the difference between the new and old value divided by the old value, multiplied by 100. It is a simple price/value change between two points and does not account for contributions or withdrawals (which require a money-weighted or time-weighted return).
Written by Ugo Candido · Last updated May 22, 2026.