Cost Segregation Savings Calculator: Estimate Your First-Year Tax Deduction

By Zawwad Ul Sami, Founder, WeCostSegPublished: 2026-05-14Last updated: 2026-05-14

Enter your property details below for a first-year deduction estimate. The model uses industry-typical component allocations by property type, the bonus depreciation rate that applies under OBBBA based on your acquisition date, and your combined federal and state marginal rate.

Cost Segregation Savings Calculator

Estimate only. A real engineering study uses property-specific component data and is materially more precise.

Purchase price ($)

Land value ($). Leave blank for 20% default.

Property type

Placed-in-service date

Binding-contract date (optional)

Federal marginal rate: 32%

State marginal rate: 0%

Without cost seg

First-year deduction: $10,909
First-year tax savings: $3,491

With cost seg

First-year deduction: $172,909
First-year tax savings: $55,331
Bonus rate applied: 100%

Estimated first-year lift: $51,840 in tax savings vs straight-line depreciation. Depreciable basis: $600,000 (land valued at $150,000). Source for allocation ranges: property type component breakdowns from IRS Pub 5653 industry guidance.

Open the full calculator with 10-year NPV →

What the calculator estimates (and what it does not)

The calculator estimates the first-year deduction you would expect from a cost segregation study, using midpoint component allocations from our property type pages. Actual results depend on property-specific data that only an engineering walkthrough can capture: condition, age, recent improvements, and the share of fixtures owned versus tenant-installed.

The assumptions baked in

Component allocations from IRS Publication 5653 industry guidance. Per-property-type ranges live on our property type pages.
Bonus depreciation rate determined by acquisition date and placed-in-service date, following Public Law 119-21 (OBBBA) and IRS Notice 2026-11.
MACRS first-year conventions: 20% for 5-year property, 5% for 15-year land improvements, half-year convention for real property.
Default land value is 20% of purchase price when not provided.

Why an engineered study is more precise

A Fully Engineered study reviews actual cost records, blueprints, and a site inspection to allocate components. The IRS Cost Segregation Audit Techniques Guide identifies six methodologies in Chapter 3, and the detailed engineering approach from actual cost records is the most defensible.

Bring this estimate into the broader strategy:

About the author

Zawwad Ul Sami, Founder

Zawwad Ul Sami is the founder of WeCostSeg, a founder-led cost segregation firm serving real estate investors across the US. He focuses on strategy, pricing, and the firm's overall direction.