Section 179 Calculator — Methodology

Step-by-step calculation

See whether Section 179 immediate expensing or MACRS 5-year depreciation produces more present-value savings for your equipment purchase.

1. 1

   Enter equipment cost

   Total purchase price of qualifying business equipment.

2. 2

   Set your marginal tax rate

   Federal + state combined effective rate.

3. 3

   Set discount rate for NPV

   5% is a reasonable default time-value-of-money assumption.

4. 4

   Read the NPV advantage

   Section 179 normally wins by 10-15% of present value, unless you lack year-1 taxable income to absorb the full deduction.

Assumptions and overrides

Compares Section 179 immediate expensing against straight MACRS 5-year half-year-convention depreciation. Doesn't model bonus depreciation interaction (currently phasing down 60%/40%/20%/0% across 2024-2027). Also assumes the business has sufficient taxable income to absorb the Section 179 deduction — excess is carried forward, not refunded.

Every region default on the calculator is editable. If your effective rate, fee, or threshold differs from the headline figure shown, type your own number into the field — the calculator recomputes instantly without leaving this page.

Review cadence and corrections

This methodology and the underlying rate defaults are reviewed at least annually, and immediately following any change to the headline rate from IRS, HMRC, or SARS. Every substantive update is recorded on the public changelog. Spotted an error? See the corrections policy for how to report it.

See the full editorial policy for the standards every page on BusCalcTools is held to.