Investment Return Calculator
Raw account growth is misleading when you’ve added or removed money along the way. This calculator uses the Modified Dietz method to estimate your true investment performance.
Total Gain
$11,000
Total Return
39.29%
Annualized Return
11.68%
CAGR (ignoring flows)
18.88%
simple begin→end growth rate
Modified Dietz return
R = (End − Begin − NetFlows) / (Begin + 0.5 × NetFlows)Net flows (deposits minus withdrawals) are weighted at 50%, approximating mid-period timing. Annualized return is (1 + R)^(1/years) − 1.
How It Works
- 1Your gain is what’s left after subtracting both your starting value and the net money you added.
- 2Deposits are half-weighted because money added mid-period had less time to grow.
- 3The annualized figure lets you compare performance against benchmarks like the S&P 500.
Frequently Asked Questions
Why is my return lower than my account growth?
Because deposits aren’t investment gains. If your account grew from $25k to $42k but you deposited $6k, only $11k is actual return.
What’s the difference between annualized return and CAGR?
CAGR ignores cash flows entirely — it only compares beginning and ending value. The annualized (Dietz) figure adjusts for money you added or removed.
How accurate is the Modified Dietz method?
It’s the industry standard approximation when exact cash-flow dates aren’t known. For flows spread evenly through the period it’s very close to a true time-weighted return.
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