How to Estimate the Present Value of Depreciation Tax Benefits

To estimate the present value of depreciation tax benefits, calculate each year’s depreciation deduction under the asset’s MACRS schedule, multiply by your marginal tax rate to get the annual tax shield, discount each shield back to today at your cost of capital, and sum the results. For a $100,000 piece of equipment on a 5-year MACRS schedule at a 21% corporate tax rate and an 8% discount rate, that sum is roughly $17,038. Claim 100% bonus depreciation instead and the figure climbs to about $19,444, because the entire deduction lands in year one and barely loses anything to discounting. Subtract that present-value number from the purchase price and you have the true after-tax cost of the asset.

The Three Inputs You Need First

Three numbers drive the whole calculation. Get any of them wrong and the answer is wrong.

Cost basis. Federal tax law sets the basis of property as its cost.1Office of the Law Revision Counsel. 26 U.S.C. 1012 – Basis of Property Cost That is more than the sticker price. The IRS includes sales tax, freight, installation, and testing in the depreciable cost.2Internal Revenue Service. Publication 551 – Basis of Assets Leaving those out can understate the tax benefit by thousands on heavy equipment.

Marginal tax rate. This tells you how many cents of tax you save per dollar of depreciation. C corporations pay a flat 21% federal rate, so $1,000 of depreciation saves $210. Sole proprietors, partnerships, and S corporation shareholders use individual brackets running from 10% to 37%. State income tax stacks on top; in a state with a 5% corporate rate, each dollar of depreciation is worth 26 cents, not 21.

Discount rate. A dollar saved five years from now is worth less than a dollar today, and the discount rate is how you measure the gap. Most businesses use their weighted average cost of capital. Without a formal WACC, a reasonable stand-in is the borrowing rate on similar-term debt, or an intermediate-term Treasury yield plus a risk premium. Higher discount rates shrink later deductions, which is why accelerated methods and bonus depreciation are worth so much.

Pick the Recovery Period

Federal law sorts depreciable assets into classes with fixed recovery periods.3Office of the Law Revision Counsel. 26 U.S.C. 168 – Accelerated Cost Recovery System The common ones for business property:

The recovery period is the single biggest lever on present value. A $100,000 deduction spread over 5 years produces far more present-value benefit than the same $100,000 spread over 39 years, even though the total undiscounted tax savings are identical.

One convention note that changes the arithmetic: personal property under the default half-year convention is treated as placed in service at the midpoint of year one, so a 5-year asset actually produces deductions across six tax years, a half-year at each end and full years in between.5Office of the Law Revision Counsel. 26 U.S.C. 168 – Accelerated Cost Recovery System – Section: Applicable Convention

Calculate the Annual Tax Shield Under MACRS

For 5-year property under the 200% declining balance method with the half-year convention, the IRS prescribes these annual percentages:

  • Year 1: 20.00%
  • Year 2: 32.00%
  • Year 3: 19.20%
  • Year 4: 11.52%
  • Year 5: 11.52%
  • Year 6: 5.76%

They add up to 100% across six tax years.4Internal Revenue Service. Publication 946 – How To Depreciate Property Multiply each year’s percentage by the cost basis, then by the marginal tax rate, to get that year’s tax shield. On a $100,000 asset at 21%:

  • Year 1: $100,000 × 20.00% × 21% = $4,200
  • Year 2: $100,000 × 32.00% × 21% = $6,720
  • Year 3: $100,000 × 19.20% × 21% = $4,032
  • Year 4: $100,000 × 11.52% × 21% = $2,419
  • Year 5: $100,000 × 11.52% × 21% = $2,419
  • Year 6: $100,000 × 5.76% × 21% = $1,210

The undiscounted total is $21,000. Depreciation is a non-cash expense, so no money leaves the business when the deduction is claimed; the benefit shows up as a smaller tax check each year.

Discount Each Year Back to Today

Divide each year’s tax shield by (1 + r) raised to the power of the year it lands in, where r is the discount rate. At 8%:

  • Year 1: $4,200 ÷ 1.08 = $3,889
  • Year 2: $6,720 ÷ 1.1664 = $5,761
  • Year 3: $4,032 ÷ 1.2597 = $3,201
  • Year 4: $2,419 ÷ 1.3605 = $1,778
  • Year 5: $2,419 ÷ 1.4693 = $1,647
  • Year 6: $1,210 ÷ 1.5869 = $762

Sum: about $17,038. That is the present value of the depreciation tax benefits on this asset. Subtract it from the $100,000 purchase price and the real economic cost is closer to $82,962. That adjusted figure belongs in any net present value or internal rate of return analysis, not the gross price.

The same method scales up. A $500,000 residential rental building, land excluded, depreciated straight-line over 27.5 years produces roughly $18,182 of depreciation per year and a $3,818 annual tax shield at 21%. Discounted at 8%, the present value across 27.5 years lands near $43,300, only about 8.7% of the building’s cost. The same $500,000 in 5-year equipment produces around $85,200 in present-value savings under standard MACRS. Recovery period does most of the work.

When Bonus Depreciation or Section 179 Collapses the Math

Two provisions can shove the whole deduction into year one, which makes the discounting almost irrelevant.

100% Bonus Depreciation

Under the One Big Beautiful Bill Act, signed in 2025, 100% first-year bonus depreciation is permanent for qualifying property acquired after January 19, 2025.6Internal Revenue Service. Treasury, IRS Issue Guidance on the Additional First Year Depreciation Deduction Amended as Part of the One Big Beautiful Bill Eligible property is tangible assets with a MACRS class life of 20 years or less, which covers most equipment, vehicles, and furniture. There is no annual dollar cap, and bonus depreciation can create a net operating loss.

The present-value calculation simplifies to one step: cost basis × tax rate, discounted by one year. For a $100,000 asset at 21%, that is a $21,000 tax shield. At an 8% discount rate, present value is $19,444. The $2,400 gap versus standard MACRS on the same asset is pure time-value loss from waiting six years for the deductions. At higher discount rates, the gap widens.

Section 179 Expensing

Section 179 lets you deduct the full cost of qualifying equipment in the year it goes into service, up to $2,560,000 for 2026. The deduction phases out dollar-for-dollar once qualifying property placed in service that year exceeds $4,090,000. Unlike bonus depreciation, Section 179 cannot exceed taxable business income for the year. Excess carries forward, but the delay costs present value.

When you can use the full deduction in year one, the math matches bonus depreciation: cost × rate, discounted one year. If income won’t absorb the full amount, split the calculation between the current-year piece and the carried-forward piece, discounting each at its respective year.

Subtract the Present Value of Recapture

The tax savings from depreciation are not free forever. When you sell the asset for more than its depreciated book value, the IRS claws back some of those deductions through recapture. A thorough present-value estimate accounts for it.

Equipment, vehicles, and other tangible personal property fall under Section 1245. The portion of any gain on sale attributable to prior depreciation is taxed as ordinary income, not at capital gains rates. The recaptured amount is the lesser of total depreciation claimed or the actual gain. Section 179 property is treated as Section 1245 property for this purpose.7Office of the Law Revision Counsel. 26 U.S.C. 1245 – Gain From Dispositions of Certain Depreciable Property

Buildings and structural components fall under Section 1250. Because most real property uses straight-line depreciation, the “additional depreciation” subject to full ordinary-income recapture is typically zero.8Office of the Law Revision Counsel. 26 U.S.C. 1250 – Gain From Dispositions of Certain Depreciable Realty The gain attributable to straight-line depreciation is instead taxed at a maximum 25% as unrecaptured Section 1250 gain, higher than the standard long-term capital gains rate.9Internal Revenue Service. Treasury Decision 8836 – Unrecaptured Section 1250 Gain

To fold recapture into the estimate, project the expected sale price and year of disposal, calculate the recapture tax, discount that future payment back to today, and subtract it from the present-value depreciation benefit. For equipment you plan to run until it’s worthless, recapture is zero. For appreciating real estate, ignoring recapture can overstate the net benefit substantially.

Watch for NOLs and Rate Changes

Large depreciation deductions, especially with bonus depreciation, can push a business into a net operating loss. NOL carryforwards generated in 2021 and later can offset only 80% of taxable income in any future year, so the tax benefit may arrive later than the MACRS schedule suggests. If the present-value estimate assumes each dollar of depreciation reduces tax dollar-for-dollar in its year, but the business is in a loss position, the real benefit is deferred and its present value shrinks. When early-year losses are realistic, model the year each dollar of depreciation actually produces a cash tax saving rather than assuming it follows the schedule.

The same caution applies to rate changes. If income will move you across brackets during the recovery period, a single marginal rate for every year is an approximation. Assigning a projected rate to each year improves accuracy, though for most planning work a single rate is close enough.