How to Calculate Rental Property Cost Basis

Add costs associated with all items listed above to your original $300,000 purchase price to arrive at your original cost basis.

Closing cost items you cannot add to your original cost basis might include:

• Insurance premiums for casualty (fire, hurricane, etc.)
• Rent or utility charges for occupancy prior to closing
• Property taxes
• Loan and refinancing costs or fees (points, appraisal, etc.)
• Pre-paid interest on your loan(s)
• Lender’s title insurance
• Amounts placed in escrow to cover future expenses

The first three items on this list can be deducted as normal expenses for the year in which you acquired the property. Loan costs are not deducted but are instead amortized over the expected life of the loan. Amounts placed into escrow accounts are not deducted until the actual expenses are incurred and paid.

Step 2: Add Capital Expenses for Adjusted Cost Basis

Adjusted cost basis = original basis + capital improvements made after purchase.

Capital improvements are typically expenses that:

• Add value to the property
• Extend its useful life substantially
• Adapt it to a new use

Examples: new roof, HVAC replacement, kitchen renovation, adding a bedroom, new driveway, major electrical/plumbing upgrades.

NOT capital improvements: Minor repairs, recurring yard work, painting (unless part of larger renovation), and routine maintenance.

Example continued:

• Original basis: $305,000
• New master bathroom: $22,000
• HVAC system replacement: $8,500
• Adjusted cost basis: $335,500

Special Case: Property Not Immediately Rent-Ready

If your rental wasn’t ready to occupy when you bought it, you usually capitalize all preparation costs incurred prior to the unit being ready for rental, even items that would normally be expenses.

Let’s say you fixed some foundation issues, replaced carpeting, painted everything, and deep cleaned before your first tenant moved in. You would typically add all of these costs to your adjusted basis.

Extended example:

• Original basis: $305,000
• Bathroom renovation: $22,000
• HVAC replacement: $8,500
• Pre-rental repairs: $1,200
• Pre-rental cleaning: $400
• Adjusted cost basis: $337,100

Once the property is in service (ready for tenants), similar costs would usually be deducted as expenses in the year incurred instead.

Step 3: Calculate Depreciation Basis (The Tricky Part)

Here’s what often trips up landlords and investors: you can’t depreciate your entire adjusted cost basis. Land doesn’t depreciate. Only the building and improvements do.

To solve this, you need to allocate your purchase price between land and improvements and there are typically several acceptable methods:

Method 1: Property Tax Assessment Check your county tax bill. If the assessor allocated 20% to land and 80% to improvements, you can use that same ratio.

Method 2: Appraisal If you have an appraisal that breaks out land value separately, you may be able to use those numbers, assuming they are reasonable and defensible.

Method 3: Comparable Sales This is a more advanced method that should only be pursued with the guidance of a CPA. In some cases, you can look at recent land-only sales in the area to establish land value, although this is a risky approach and can sometimes leave too much room for dispute.

Example using tax assessment method:

• County assessor: 22% land, 78% improvements
• Original purchase price: $300,000
• Land value: $300,000 × 22% = $66,000
• Improvements value: $300,000 × 78% = $234,000

Now add any capital expenses made in your first year of ownership:

• Improvements from purchase price: $234,000
• Capitalizable closing costs: $5,000
• Bathroom renovation: $22,000
• HVAC replacement: $8,500
• Pre-rental costs: $1,600
• Depreciation basis (Year 1): $271,100

Depreciate this over 27.5 years (for residential rental property):

• Annual depreciation: $271,100 ÷ 27.5 = $9,858 per full year

Note: Your first year depreciation expense will of course be prorated based on when you placed the property in service. If you started renting in July, you would usually get roughly 5.5/12 of the annual deduction in that first year of ownership.

Common Mistakes to Avoid

1. Using adjusted cost basis for depreciation
Your $337,100 adjusted cost basis includes $66,000 of land value. You can’t depreciate land. Always subtract land value first.

2. Forgetting to track capital improvements
Every roof replacement, major system upgrade, and significant improvement increases your adjusted basis. Track these meticulously as they can generate depreciation deductions during your period of ownership and also may lower your capital gains when you sell.

3. Capitalizing costs that should be expensed
Property taxes, insurance, and loan fees don’t contribute to your basis. You’ll lose current-year deductions if you add them incorrectly.

4. Not documenting the land/building allocation
Use your county assessment, appraisal, or other supportable method and document your approach clearly. The IRS may challenge your allocations.

5. Confusing repairs with improvements
Replacing a broken water heater with a similar model? That’s usually a repair, which then may be deductible. But if you’re upgrading to a new tankless system when you had a traditional tank water heater previously, that’s typically an improvement, which would usually be capitalized.

Why Getting This Right Matters

Getting your cost basis right has two major impacts:

Impact #1: Annual Depreciation Higher depreciation basis = larger annual deduction = lower taxable income. If you miscalculate and claim too little, you may be overpaying on your taxes every year.

Impact #2: Capital Gains on Sale When you sell, your gain = sale price minus adjusted basis. Lower basis = higher taxable gain. If you didn’t track all of your capital improvements, you may end up paying capital gains tax on money you actually invested in improvements.

Get the Free Cost Basis Spreadsheet

Tracking all of this manually in a notebook or scattered receipts in shoeboxes is asking for trouble. Instead, download our free rental property cost basis spreadsheet that works to:

• Help you prepare for tax time and eventual sale
• Calculate original cost basis automatically from your inputs
• Track capital improvements year by year
• Separate land value for depreciation based on your inputs
• Calculate your projected annual depreciation deduction
• Show your current adjusted basis in real-time