Financial calculator
Three-Fund Portfolio Calculator
Set your three target weights — US stocks, international stocks, and bonds — enter an amount to invest, and see exactly how many dollars go into each fund. The classic three-fund split, computed instantly.
How to use this calculator
Keep the default 60/30/10 split or enter your own weights and fund tickers, then set the amount to invest. The table returns the percentage and the dollar amount for each fund; if your weights do not add up to 100% they are normalized for you.
Inputs are editable, results update locally in the browser, and outputs are informational arithmetic based only on the weights and amount you enter — not a recommendation to buy any security.
What a three-fund portfolio is
A three-fund portfolio holds just three broad index funds — total US stock market, total international stock market, and total bond market — for wide diversification at very low cost. It is popular with Boglehead-style investors because it is simple to hold and easy to rebalance.
This builder does the allocation arithmetic: you choose the weights, and it splits any amount across the three funds.
How to choose your weights
There is no single correct split — common starting points range from stock-heavy mixes like 80/20 to balanced 60/40 profiles, with bonds often scaled up as the time horizon shortens. The weights you enter are your own assumptions, not a recommendation.
Once you have set and funded the mix, use the rebalancing calculator to bring it back to these weights as the market moves it around.
Data notice: Market data may be delayed, incomplete, or unavailable for some securities. Metrics are provided for informational purposes only.
Last updated:
Calculator notes
- The calculator runs in the browser and keeps the assumptions visible to the reader.
- Inputs are transparent and editable, which makes the assumptions visible to the reader.
- Results are estimates for informational purposes and can be compared with stock and ETF research pages.
Financial disclaimer
This website provides informational content only and is not financial advice. We do not recommend buying or selling securities. Market data may be delayed, incomplete, or inaccurate. Always verify information with official sources before making financial decisions.
FAQ
What is a three-fund portfolio calculator?
It splits an amount you enter across three index funds by the target weights you choose — typically US stocks, international stocks, and bonds — and shows the dollar amount for each.
Can I use my own weights and funds?
Yes. Edit the fund names or tickers and the target percentages. If the weights do not sum to 100%, they are normalized so the split still adds up to your full amount.
What is a common three-fund split?
Common starting points include 60/30/10 or 80/20 stock/bond profiles, with more bonds as the time horizon shortens. The right split is your own assumption — this tool only does the arithmetic.
How do I keep the allocation on target later?
As prices move, the mix drifts. Use the rebalancing calculator to see the buy/sell amounts that return each fund to these weights, or add new contributions to the underweight fund.