How to use the glide path allocation calculator
- Enter your stock share today, your stock share at the end and the number of years between them.
- Choose whether the change happens a little every year or in steps and, for steps, how many years pass between them.
- Optionally enter a portfolio amount to see dollars in stocks and in bonds and cash each year.
- Read the table of shares by year and the largest one-year change.
Formula
even path: share in year t = start + (end - start) x t / years
stepped path: share = start + (end - start) x steps taken / total steps
bonds and cash = 100% - stock share
With steps, the total number of steps is the years divided by the step length, rounded up. The last step always lands on the final year, so the end share is exactly the one you entered.
From 90% stocks to 40% over 30 years
An even path loses 50 points over 30 years, which is 1.67 points a year. Year 15 sits at 65% stocks and 35% bonds and cash, and year 30 reaches 40% and 60%.
In steps, a move from 80% to 30% over 25 years with a step every 5 years has five equal steps of 10 points. Years 0 to 4 hold 80%, years 5 to 9 hold 70%, then 60%, 50% and 40%, and year 25 reaches 30%. With a $200,000 portfolio and a path from 70% to 50% over 10 years, year 0 shows $140,000 in stocks and $60,000 in other assets.
What a glide path is
A glide path is a plan that lowers the share of stocks over time, usually as a goal such as retirement gets closer. The plan is a schedule you decide in advance, which helps avoid changing the mix on impulse. Target-date funds follow this idea.
This page shows a schedule only
The dollar columns apply each share to a fixed amount and ignore growth, deposits and trading costs. It does not choose a start, an end or a shape for you. To act on a schedule, the Portfolio Rebalancing Calculator shows the trades needed to reach a target mix, and the Two-Asset Portfolio Calculator shows how a mix affects risk and return.
Assumptions and limits
- Shares are percentages of the total portfolio held in stocks, with the rest in bonds and cash.
- The path is a plan. Actual shares drift with market moves between rebalances.
- Dollar amounts assume a fixed portfolio with no growth.
- Starting and ending shares are examples to replace with your own plan.
Frequently asked questions
What does a stepped path do differently?
Instead of changing the mix a little every year, it holds the mix constant for a number of years and then makes a larger move. It means fewer changes but bigger ones.
Can the stock share rise over time?
Yes. Enter an ending share higher than the starting share. The table then shows an increasing stock share, for example for a plan that adds risk gradually.
Why does the last step shorten when the years do not divide evenly?
The total number of steps is rounded up, and the final year always uses the last step. This way the end share always matches the number you entered.
Is a particular glide path recommended?
No. This page lays out the arithmetic of a path you choose. It does not say what start, end or shape suits you.