MACRS Depreciation Calculator
Calculate ITC savings, MACRS depreciation deductions, and effective net system cost for commercial solar. Includes bonus depreciation schedules, state conformity, NPV — free, no signup.
MACRS Solar Depreciation Calculator
Enter system cost, ITC rate, and bonus depreciation year. Get year-by-year MACRS deductions, federal and state tax savings, NPV, and effective net system cost after all incentives.
| Tax Year | Depreciation Rate | Deduction | Fed Tax Savings | Cumulative |
|---|
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What This MACRS Calculator Covers
Federal ITC, MACRS depreciation, bonus depreciation, state conformity, and NPV - all in one tool for commercial solar tax benefit estimation. For educational and estimation purposes. Consult a CPA before filing.
ITC + Basis Reduction
Calculates ITC amount (30%, 40%, or 50% for energy community / domestic content stacking), applies the mandatory 50% ITC basis reduction, and outputs the correct depreciable basis per IRS rules.
Bonus + MACRS Schedule
Applies the correct bonus depreciation rate by placed-in-service year (100% restored for 2025+ under OBBBA), then applies IRS Publication 946 GDS 5-year or ADS 12-year rates to the remaining basis. Year-by-year deduction table included.
NPV & Net System Cost
Discounts all future tax savings at your WACC or required return rate. Shows effective net system cost after ITC and MACRS, with an incentive stack bar breaking down each component as a percentage of gross cost.
Key Features
Built for commercial solar developers, EPCs, tax equity investors, and CPAs estimating federal and state tax benefits on business-owned solar systems.
2022–2027+ Bonus Depreciation Schedule
Auto-fills the correct bonus rate by year: 100% (pre-2023), 80% (2023), 60% (2024), 40% (Jan 1–19, 2025), 100% (Jan 20, 2025+ per OBBBA). Manual override available.
ITC Adder Stacking (Up to 50%)
Models all three ITC tiers: 30% base (Section 48E), +10% energy community adder, +10% domestic content adder. Stacking to 50% reduces effective system cost by half before depreciation.
GDS vs ADS Depreciation Systems
GDS 5-year (fastest deductions, recommended for most commercial solar) vs ADS 12-year (required for certain partnerships, tax-exempt financed property, or foreign use). Uses exact IRS Publication 946 rate tables.
Half-Year vs Mid-Quarter Convention
Half-year convention (standard for most placements). Mid-quarter convention required if more than 40% of depreciable property is placed in service in Q4 - significantly reduces Year 1 deductions for Q4 projects.
State Depreciation Conformity
Enable state depreciation and toggle conformity to federal bonus. Non-conforming states (CA, NY, NJ, IL, PA, and others) use straight-line 5-year [10/20/20/20/20/10%] instead of bonus - a common source of modeling errors.
Printable Depreciation Schedule
Year-by-year table showing depreciation rate, deduction amount, federal tax savings, and cumulative total. Bonus year rows are labeled with a green badge. Print or save directly from the table header.
How to Use This Calculator
Four inputs drive all outputs. Results update instantly as you adjust any field.
Enter gross system cost and ITC rate
Enter the total installed system cost before any incentives. Select the applicable ITC rate: 30% for standard commercial (Section 48E), 40% if the project is in a designated energy community, or 50% with both the energy community and domestic content adders. The tool immediately shows ITC amount, 50% basis reduction, and depreciable basis.
Set placed-in-service year and depreciation method
Select the year the system will be placed in service. The bonus depreciation rate auto-fills based on the Tax Cuts and Jobs Act phase-down schedule and the OBBBA restoration (100% for systems placed in service after January 19, 2025). Choose GDS 5-year (recommended for commercial solar) or ADS 12-year if required. Select half-year convention (default) or mid-quarter if your situation requires it.
Set tax rate and discount rate
Enter the combined federal and state marginal tax rate - the default 25% works for most C-corporations (21% federal + ~4% blended state). The discount rate (default 7%) is used to calculate NPV of all tax benefits. Use your WACC or required return for a project-specific analysis.
Optionally add state depreciation
Enable the state depreciation section to model additional state tax savings. Enter your state tax rate and check whether your state conforms to federal bonus depreciation. Major non-conforming states include California, New York, New Jersey, Illinois, and Pennsylvania - uncheck the conformity box for these and the tool applies straight-line 5-year instead.
Read the results
The results panel shows effective net system cost, total tax benefit, NPV of all savings, and an incentive stack bar breaking down ITC, MACRS, and state components as percentages of gross cost. The year-by-year depreciation schedule table shows each deduction, the tax savings it generates, and cumulative totals through the full recovery period.
Calculation Methodology
Based on IRS Publication 946, IRC Section 48E, and the One Big Beautiful Budget Act (OBBBA) bonus depreciation restoration. All formulas are transparent and verifiable.
Step 1 - ITC and Depreciable Basis
ITC Amount = System Cost × ITC Rate
ITC Basis Reduction = ITC Amount × 50%
Depreciable Basis = System Cost − ITC Basis Reduction
IRS requires reducing the depreciable basis by 50% of the ITC claimed - not the full ITC. On a $100,000 system at 30% ITC: ITC = $30,000; basis reduction = $15,000; depreciable basis = $85,000. This mandatory reduction is the most common MACRS modeling error.
Step 2 - Bonus Depreciation
Bonus Deduction = Depreciable Basis × Bonus %
Remaining Basis = Depreciable Basis − Bonus Deduction
With 100% bonus (2025+), the entire depreciable basis is deducted in Year 1. The remaining MACRS schedule applies only to any basis not taken as bonus. For 60% bonus (2024): $85,000 × 60% = $51,000 bonus deduction; $34,000 remaining for the 5-year MACRS schedule.
Step 3 - MACRS Rate Tables (IRS Pub. 946)
GDS 5-year Half-Year: [20%, 32%, 19.2%, 11.52%, 11.52%, 5.76%]
ADS 12-year Half-Year: [4.167%, 8.333%×10, 4.167%]
State SL 5-year (non-conforming): [10%, 20%, 20%, 20%, 20%, 10%]
GDS 5-year uses double-declining balance switching to straight-line - MACRS's fastest depreciation method for solar. The 6-year recovery (5-year property under half-year convention) means deductions extend one year beyond the recovery class. Mid-quarter Q4 rates: [5%, 38%, 22.8%, 13.68%, 10.94%, 9.58%] - Year 1 drops from 20% to 5% for late-year placements.
Step 4 - NPV of Tax Benefits
NPV of ITC = ITC Savings / (1 + r)^1
NPV of MACRS = Σ [ (Year Deduction × Tax Rate) / (1 + r)^year ]
Total NPV = NPV of ITC + NPV of MACRS + NPV of State (if enabled)
Discounting matters most for the MACRS portion - tax savings received in years 2–6 are worth less than Year 1 savings. With 100% bonus depreciation, the entire MACRS benefit is realized in Year 1, maximizing NPV. With 60% bonus (2024), the remaining 40% is spread over years 2–6 at reduced present value.
Bonus Depreciation Schedule by Placed-in-Service Year
The Tax Cuts and Jobs Act of 2017 phased down bonus depreciation from 100% starting in 2023. The One Big Beautiful Budget Act (signed July 4, 2025) permanently restored 100% bonus for property placed in service after January 19, 2025.
| Placed-in-Service Period | Bonus Depreciation Rate | Authority | Year 1 Deduction (on $85K basis) |
|---|---|---|---|
| Before Jan 1, 2023 | 100% | TCJA 2017 | $85,000 |
| 2023 | 80% | TCJA phase-down | $68,000 + MACRS on $17,000 |
| 2024 | 60% | TCJA phase-down | $51,000 + MACRS on $34,000 |
| Jan 1 – Jan 19, 2025 | 40% | TCJA phase-down | $34,000 + MACRS on $51,000 |
| Jan 20, 2025 – 2026+ | 100% (permanent) | OBBBA (July 4, 2025) | $85,000 |
Example basis = $85,000 (from $100,000 system at 30% ITC, 50% basis reduction). Year 1 deductions shown before applying the 20% GDS Year 1 rate to remaining basis. MACRS on remaining basis generates additional deductions in years 2–6.
Federal ITC Rates: Base + Adders (Section 48E)
Commercial solar (Section 48E) starts at 30% and can stack up to two 10% adders. Each adder has specific qualification requirements under the Inflation Reduction Act.
| ITC Rate | Qualification Requirement | ITC on $1M System | Depreciable Basis |
|---|---|---|---|
| 30% | Base rate - all commercial solar (Section 48E). Prevailing wage + apprenticeship required for systems above 1 MW. | $300,000 | $850,000 |
| 40% | 30% base + 10% energy community adder. Project sited in a qualifying coal closure area, brownfield, or fossil fuel employment community per IRS Notice 2023-29. | $400,000 | $800,000 |
| 50% | 40% + 10% domestic content adder. Requires IRS-specified percentages of US-manufactured steel, iron, and manufactured products. Detailed under IRS Notice 2023-38 and Notice 2024-41. | $500,000 | $750,000 |
Section 25D residential ITC expired December 31, 2025. Commercial Section 48E remains 30% base through at least 2032. Consult a tax attorney to verify adder qualification before filing.
Who Uses This Tool
Any party modeling commercial solar tax economics - from the first feasibility call to tax equity term sheet review.
Commercial Solar Developers & EPCs
Quickly model the after-tax cost of a commercial project for a customer presentation or LOI. Compare 30% vs 40% vs 50% ITC scenarios to show the financial impact of siting in an energy community or meeting domestic content requirements. The effective net cost figure gives customers a clear headline number.
Tax Equity Investors & Accountants
Verify the depreciable basis calculation (the ITC basis reduction step is frequently modeled incorrectly). Cross-check year-by-year MACRS deductions against IRS Publication 946 rate tables. Model mid-quarter convention impact for Q4 project closings. Use the NPV output as a starting point for tax equity yield analysis.
C&I Solar Sales Teams
Show a business owner or CFO the real after-tax cost of going solar in a first meeting. The incentive stack bar - showing ITC, MACRS, and state as percentages of gross cost - is a compelling visual. The effective net cost after all incentives is the number that drives commercial solar decisions.
Finance Teams & CFOs Evaluating Solar
Run the numbers before a capital allocation decision. Adjust the discount rate to match your hurdle rate or WACC. Enable state depreciation to capture state tax savings your CPA may not have modeled. Compare the NPV of tax benefits to the investment required to understand the true after-tax ROI of owned solar.
Pro Tips
The 50% basis reduction is mandatory - not optional
If claiming the ITC, IRS requires reducing the depreciable basis by 50% of the credit claimed - regardless of ITC rate. On a $100,000 system at 30% ITC, you lose $15,000 of depreciable basis. This is not a choice. Systems that elect out of the ITC retain the full basis. The calculator always applies this reduction correctly when any ITC rate above 0% is selected.
Avoid Q4 placement for maximum Year 1 depreciation
If more than 40% of your depreciable property is placed in service in Q4, mid-quarter convention applies to all personal property placed in service that year. For solar under GDS, this reduces the Year 1 rate from 20% to 5% (Q4 mid-quarter). Plan project completion timelines to avoid this - place in service by September 30 if possible, especially for projects that will trigger the 40% threshold.
California, New York, and most large states don't conform to bonus depreciation
Most blue-state corporate taxpayers must add back federal bonus depreciation and depreciate assets on a straight-line schedule for state taxes. This means state MACRS savings are spread over 6 years instead of realized in Year 1. Enable the state depreciation section, uncheck "Conforms to Federal Bonus," and enter your effective state rate to see the correctly modeled state benefit - which is significantly smaller than the federal benefit in non-conforming states.
100% bonus + 30% ITC can bring effective cost to ~50% of gross for many projects
At 30% ITC and 100% bonus depreciation with a 25% combined tax rate: ITC savings = $30,000 on a $100K system; MACRS tax savings = $85,000 × 25% = $21,250; total = $51,250. Effective net cost = $48,750 - about 49% of gross cost. In an energy community with the 40% ITC, effective cost drops to ~38%. This is the "real cost" number that drives commercial solar ROI calculations.
Frequently Asked Questions
Does MACRS depreciation apply to residential solar?
Why is the depreciable basis reduced by only 50% of the ITC, not the full ITC?
What is the OBBBA and how does it affect solar depreciation?
What is an energy community and how do I know if my project qualifies?
Should I elect out of the ITC to preserve the full depreciable basis?
Can I use this calculator for solar + battery storage systems?
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