Somebody at a dinner party once told me their investment "doubled in five years" like it was a mic-drop moment. And sure, doubling your money sounds great — but doubling in 5 years and doubling in 15 years are wildly different achievements. One is a home run. The other is roughly what a boring index fund does anyway.
The number that actually lets you compare the two is CAGR — Compound Annual Growth Rate. It's the single annualized growth rate that answers the question everyone actually wants answered: "On average, how fast did this grow per year?"
If you've ever tried to compare two investments held for different lengths of time, sized up a stock's historical performance, or wondered whether your side-hustle savings account is actually pulling its weight, CAGR is the metric you reach for. We built a free calculator that does the math for you — including the messy part most calculators skip.
The problem with most CAGR calculators
Plug "Beginning Value," "Ending Value," and "Years" into a basic CAGR formula and you'll get an answer. The problem is that formula assumes your money sat there untouched the whole time — no extra deposits, no withdrawals.
In reality, almost nobody's investing life works that way. You top up a brokerage account every month. You pull money out of a rental property fund for repairs. You add to a retirement account with every paycheck. Feed those raw numbers into a plain CAGR formula and the result gets distorted — some of that "growth" isn't growth at all, it's just money you put in yourself.
That's the gap our CAGR Calculator With Extra Cash Flows is built to close.
What the calculator does differently
Alongside the three inputs every CAGR calculator needs — Beginning Value, Ending Value, and Number of Years — ours adds two optional fields:
- Additional Contributions ($ per Year) — money you added along the way
- Additional Withdrawals ($ per Year) — money you took out along the way
Leave them both at 0 and it behaves exactly like a standard CAGR calculator. But if you've been contributing or withdrawing, the calculator strips that cash flow out of the Ending Value before annualizing, so the CAGR you get back reflects how the investment itself performed — not how disciplined you were about making deposits.
It also gives you:
- A Total Growth figure alongside CAGR, so you can see the raw, non-annualized change
- A breakdown of Total Contributions and Total Withdrawals over the period
- A chart plotting your projected value at the calculated CAGR against your actual Beginning and Ending Value, so the growth curve isn't just a number — you can see it
A quick example
Say you started with $10,000, added $500 a year, and five years later the account sits at $20,000.
Naively, that looks like a 100% gain — a jaw-dropping ~14.9% annualized. But $2,500 of that ending balance is money you put in yourself, not growth. Strip it out, and the real story is an investment that grew at roughly 11.84% per year. Still solid — just not quite the number the headline figure suggested.
That's the difference between measuring your investment and measuring your savings habit.
Who this is useful for
- Stock and fund investors comparing historical performance across different holding periods
- DIY retirement savers who contribute regularly and want to know if their portfolio's actual returns are keeping pace with their goals
- Landlords and small business owners tracking growth on assets that see periodic cash injections or withdrawals
- Anyone benchmarking an investment against inflation, an index, or a personal target rate
Infographic explaining CAGR, its formula, and a worked example with contributions
Adjusted ending = Ending − Contributions + Withdrawals
Try it yourself
The calculator is free, requires no sign-up, and runs entirely in your browser:
👉 CAGR Calculator With Extra Cash Flows
The page also walks through the full formula, a worked example, and answers to the questions people ask most — like why the contribution adjustment is an approximation rather than a precise XIRR calculation, and what to do if you've made withdrawals along the way.
And if you're digging into valuation more broadly, it sits alongside our other tools like the Discounted Cash Flow (DCF) Calculator and Compound Interest Calculator on Smart Calculators Hub.
Related
Calculators
If
you found this useful, these calculators on Smart Calculators Hub pair well
with it:
· Investment Return Calculator — how an investment has actually performed in dollars and in percentage terms.
· Retirement Savings Goal Calculator — personalized answer by comparing what you're on track to save against what you'll actually need.