The pretax rate of return measures an investment’s gain or loss before taxes are deducted. It helps compare investments whose earnings may face different tax treatment, but it does not show how much an investor keeps. To estimate that, compare the pretax figure with an after tax return and account for the investor’s tax rate.
How the pretax rate of return is calculated
A 4.25% after tax return, paired with a 15% tax rate, produces a 5% pretax return. The calculation reverses the effect of tax by dividing the after tax return by one minus the tax rate.
Pretax rate of return = after tax rate of return ÷ (1 minus tax rate)
For the example, the calculation is 4.25% ÷ (1 minus 0.15), or 4.25% ÷ 0.85. The result is 5%. This formula is useful when an after tax figure is known and an investor wants to compare it with returns quoted before taxes.
Most investment returns are presented before taxes because investors can face different tax bills. One person’s taxable income, filing status and holding period can affect the amount owed. A pretax figure offers a shared starting point, but it is not a forecast of the final amount in an account.
| Investment or measure | Pretax return | After tax result in the example | Key point |
|---|---|---|---|
| Stock ABC | 5% | 4.25% | Assumes a 15% capital gains tax |
| Bond XYZ, a tax exempt municipal bond | 4.25% | 4.25% | Pretax and after tax returns are equal in this example |
| Pretax return | Before tax is applied | Not shown | Useful for comparing reported performance |
| After tax return | Not applicable | After tax is applied | Reflects the return left after taxes |
The table compares the example’s returns, not every investor’s likely outcome. Bond XYZ is described as tax exempt, so the example gives it the same 4.25% return before and after tax. Stock ABC reaches the same after tax figure only after its 5% pretax return is reduced by the assumed tax.
Stock ABC and Bond XYZ show why taxes matter
Stock ABC earns a 4.25% after tax return in the example, with a 15% capital gains tax applied. Working backward gives a 5% pretax return. Bond XYZ, a tax exempt municipal bond, has a 4.25% pretax return and therefore keeps that return after tax under the example’s assumptions.
That comparison changes the way the two investments look. Stock ABC has the higher pretax return, yet its after tax return matches Bond XYZ. The source example also describes the municipal bond as safer and the stock as more volatile. An investor comparing them would need to weigh that difference alongside the return, rather than treating the pretax percentage as the whole answer.
Investment income can be taxed in more than one way. A profit from selling a security can be subject to capital gains tax. Dividends from stocks and interest from bonds may also be taxed. Because the treatment of dividends, interest and gains can differ, two investments with similar pretax performance may leave different amounts after tax.
For a practical comparison, write down the quoted pretax return, the kind of income it represents and the tax rate used in any estimate. If an after tax return is available, the formula can convert it to a pretax figure. If only a pretax return is shown, the formula alone cannot establish an investor’s personal after tax result without the relevant tax rate.
Holding period and personal tax rates affect the result
Less than one year can make a difference to how a capital gain is taxed. The source material states that short term gains on positions held for less than one year are taxed at the investor’s marginal income tax rate. Long term gains on assets held longer than one year are taxed at 0%, 15% or 20%, depending on taxable income and filing status.
Those rates mean a single pretax return does not translate into one universal after tax return. Investors with different income or filing situations can owe different amounts on the same gain. The same issue applies when income arrives as dividends or bond interest instead of a sale gain. A displayed pretax rate is therefore a comparison measure, not a personal take home estimate.
Pretax return is sometimes described as gross return or nominal return. Those labels can be broader than taxes alone: the source material notes that such figures can also leave out interest, transaction costs, commissions and fees. Check what a quoted return includes before comparing products. A number that excludes costs as well as taxes will not equal the amount ultimately retained.
For a usable estimate, identify whether the return is pretax or after tax, determine whether it comes from a sale, dividends or interest, and check the holding period and applicable tax rate. Then compare the after tax figure with the other investment’s after tax result. That is the comparison that shows what remains after tax treatment is taken into account.