Section 179 Deduction Calculator

Calculates the exact monthly payment, total interest and first-year interest for an equipment, truck, tractor, RV, land, manufactured home, ATV, pontoon or other asset loan, and, for business assets, the after-tax cost: first-year tax saving from the Section 179 or bonus deduction plus deductible interest at your marginal rate, first-year net cash, and lifetime after-tax cost. Pair it with calculate_section_179 for the deduction amount.

Finds the special (bonus) depreciation rate under IRC 168(k) from the acquisition and placed-in-service dates and applies it after any Section 179 deduction. The One Big Beautiful Bill Act made it 100% permanently for property acquired after January 19, 2025 (written binding contract date), with an election to take 40% (60% for long production property and certain aircraft) in the first tax year ending after that date. Property acquired before January 20, 2025 keeps the TCJA phase-down: 40% if placed in service in 2025 (60% long production). Rules from IRS Notice 2026-11, the 2025 Form 4562 instructions and Pub. 946.

Calculates the Section 179 expense deduction as Form 4562 Part I does, with the limits raised by the One Big Beautiful Bill Act: $2,500,000 for 2025 with a dollar-for-dollar phase-out above $4,000,000 of section 179 property (2025 Form 4562 instructions, Pub. 946), and $2,560,000 / $4,090,000 for 2026 (Rev. Proc. 2025-32 section 4.24). Applies the business income limit and reports the carryover. 2027 limits are not published yet (checked 2026-11-02) and the tool says so.

Returns the first-year write-off limits for a business vehicle by gross vehicle weight rating: passenger automobiles of 6,000 lb or less are held to the IRC 280F caps ($20,300 first year with bonus, $12,300 without, for 2026 per Rev. Proc. 2026-15; $20,200 / $12,200 for 2025 per Rev. Proc. 2025-16), heavy SUVs over 6,000 and up to 14,000 lb have a Section 179 cap of $31,300 (2025) or $32,000 (2026) with bonus depreciation for the rest, and vehicles over 14,000 lb or exempt designs have no vehicle cap. Applies the more-than-50% business use rule and scales by business use.