Adjusted Basis Calculator

Enter your original purchase price, improvements, depreciation taken, and other adjustments to calculate your asset's adjusted basis and understand its impact on capital gains.

Created by Luis GonzalezLast updated: 2026-06-08

How to Use This Calculator

1
Enter the Original Purchase Price
Input the initial cost of the asset when it was first acquired, in dollars.
2
Enter Additional Costs
Input any additional costs incurred for improvements, enhancements, or necessary expenses to the asset, in dollars.
3
Enter Depreciation Taken
Input the total amount of depreciation claimed on the asset over its useful life, in dollars.
4
Enter Other Adjustments
Input any other adjustments to the basis, such as tax credits received or casualty loss deductions, in dollars. Use a negative value for reductions.
5
Review your results
The calculator displays the Adjusted Basis, Net Adjustment, Total Increases, Total Decreases, and Basis Adjustment Ratio — showing exactly how your basis changed from the original purchase price.

Example Calculation

An investor needs to calculate the adjusted basis of a rental property purchased for $50,000, with $10,000 in improvements, $15,000 in depreciation taken, and $2,000 in other adjustments (e.g., tax credits).

Original Purchase Price ($)

50,000

Additional Costs ($)

10,000

Depreciation Taken ($)

15,000

Other Adjustments ($)

2,000

Results

Adjusted Basis

$47,000

Net Adjustment

-$3,000

Total Increases

$12,000

Total Decreases

$15,000

Adjustment Ratio

-6.00%

Tips

Distinguish Improvements from Repairs

Only capital improvements that add value or extend the life of an asset (e.g., a new roof) increase basis. Routine repairs (e.g., patching a leak) are typically deductible expenses, not basis adjustments. Check IRS Publication 527 for specifics on rental property expenses.

Track All Depreciation — Allowed or Allowable

The IRS requires you to reduce your basis by the amount of depreciation allowed or allowable, whichever is greater. Even if you didn't claim depreciation you were entitled to, the IRS treats it as if you did. In the example, the $15,000 depreciation reduces basis regardless.

Document All Adjustments

Keep meticulous records of all purchase documents, improvement invoices, depreciation schedules, and any other adjustments. Proper documentation is crucial for substantiating your adjusted basis to the IRS, especially when selling an asset and reporting capital gains or losses.

Calculating Your Asset's Adjusted Basis for Tax Planning

The Adjusted Basis Calculator determines the tax basis of an asset by factoring in its original cost, capital improvements, depreciation, and other adjustments.

For a rental property purchased at $50,000 with $10,000 in improvements, $15,000 in depreciation, and $2,000 in other adjustments, the adjusted basis is $47,000 — a 6% net reduction from the original cost.

This figure directly determines your capital gain or loss when the asset is sold.

The Formula for Adjusted Basis

The adjusted basis starts from the original cost and is modified by increases and decreases over ownership:

Adjusted Basis = Original Purchase Price + Additional Costs - Depreciation Taken + Other Adjustments

Where:

Original Purchase Price is the initial cost of acquiring the asset.
Additional Costs are expenses that add value or extend the asset's useful life (e.g., capital improvements).
Depreciation Taken is the total amount of depreciation claimed as a tax deduction.
Other Adjustments include items that either increase (like certain credits) or decrease (like casualty losses) the basis.

💡 If you've received tax credits, such as from solar energy installations, our Solar Tax Credit (ITC) Calculator can help you understand how those credits might affect your adjusted basis.

Worked Example: Calculating Rental Property Basis

Calculating the adjusted basis for a rental property:

Inputs:

Original Purchase Price: $50,000
Additional Costs (Improvements): $10,000 (e.g., new roof, HVAC system)
Depreciation Taken: $15,000 (claimed over several years)
Other Adjustments: $2,000 (e.g., a tax credit for energy-efficient upgrades)

Step-by-step:

Start with Original Purchase Price: $50,000
Add Additional Costs: $50,000 + $10,000 = $60,000
Subtract Depreciation Taken: $60,000 - $15,000 = $45,000
Add Other Adjustments: $45,000 + $2,000 = $47,000

Result cards breakdown:

Adjusted Basis: $47,000 — below original cost basis
Net Adjustment: -$3,000 (total increases $12,000 minus total decreases $15,000)
Total Increases: $12,000 (improvements + other adjustments)
Total Decreases: $15,000 (depreciation — 30% of original cost)
Basis Adjustment Ratio: -6.00% (net reduction from original price)

If sold for $100,000, the capital gain would be $100,000 - $47,000 = $53,000.

💡 For a broader understanding of your overall tax obligations, including how various income and deductions impact your bottom line, consider using a State Income Tax Calculator.

Special Rules for Basis Adjustments

Beyond simple improvements and depreciation, various scenarios trigger unique basis adjustments:

Casualty losses: If you claim a deduction for uninsured damage, reduce your basis by the deductible loss amount.
Tax credits: The Investment Tax Credit (ITC) for solar energy requires a basis reduction to prevent double benefit.
Stock splits and dividends: Modify per-share basis for securities, requiring recalculation.
Easements: Reduce basis by the amount received for granting an easement on property.
Depreciation allowed vs allowable: The IRS requires you to reduce basis by the greater of depreciation you actually claimed or could have claimed — even if you missed deductions.

IRS Publication 551 provides detailed guidance on these complex situations.

Frequently Asked Questions

What is adjusted basis in tax?

Adjusted basis is the original cost of an asset, modified by increases (capital improvements, other positive adjustments) and decreases (depreciation, casualty losses). In the example, $50,000 original cost + $10,000 improvements - $15,000 depreciation + $2,000 other adjustments = $47,000 adjusted basis. This is the value used to calculate capital gain or loss when you sell.

Why is calculating adjusted basis important for capital gains?

Capital gain = selling price minus adjusted basis. A higher adjusted basis means lower taxable gain. For the example property with a $47,000 adjusted basis, selling for $100,000 would produce a $53,000 capital gain. If you'd miscalculated the basis as $50,000 (ignoring adjustments), you'd report $50,000 gain — underpaying by $3,000 in gain, which could trigger penalties.

What types of costs increase an asset's basis?

Capital improvements that add value, prolong useful life, or adapt an asset to new uses — such as adding a room, replacing a roof, or upgrading plumbing. Other increases include certain legal fees, closing costs (title insurance), and special assessments. In the example, $10,000 in improvements plus $2,000 in other adjustments = $12,000 total increases.

What types of events decrease an asset's basis?

Depreciation is the most common decrease — the annual deduction for wear and tear on business or income-producing property. Other decreases include casualty losses, certain tax credits (like the ITC which reduces basis by half the credit amount), and insurance reimbursements. In the example, $15,000 depreciation is the only decrease, representing 30% of the original cost.

Does adjusted basis apply to all types of assets?

Yes — real estate, stocks, bonds, business equipment, vehicles, and even intangible assets like patents. For stocks, basis adjustments come from stock splits, reinvested dividends, and return of capital distributions. For personal-use assets, basis is generally only relevant when calculating a non-deductible loss.