Home Office Tax Deduction Calculator

Enter your office size and home running costs to compare the simplified flat-rate method against the actual-expense method, and see which gives you a bigger deduction. Covers the US, UK, and Canada. Nothing uploaded.

US / UK / Canada Simplified vs actual Which method wins
Estimates only, not tax advice. Figures use current published flat-rate amounts and a simplified actual-expense apportionment. They ignore depreciation, capital cost allowance, and country-specific eligibility rules (for example, US W-2 employees generally cannot claim this deduction). Speak to a tax professional before filing.

Country

Your workspace

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Result

Simplified method

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Actual-expense method

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Home Office Tax Deduction Methods Explained

How the Two Methods Work

The simplified method is quick: the US charges $5/sqft (max 300 sqft), the UK uses banded hourly rates, and Canada uses detailed square-footage apportionment. The actual-expense method takes your real costs (rent/mortgage interest, utilities, insurance) and deducts only the percentage that corresponds to your office size. For a 120 sqft office in a 1,500 sqft home, you can deduct 8% of your costs.

A Key Limitation You Must Know

In the US, W-2 employees (regular salaried workers) cannot claim a home office deduction under current tax law - only self-employed people, sole proprietors, and business owners can. The UK and Canada are more flexible, but both require the office to be your principal place of business. This calculator gives you the numbers, but you must verify your eligibility before filing.

FAQ

Which method usually saves more - simplified or actual-expense?

For most small offices, the simplified method is faster and nearly as good. But if you have a large home with expensive utilities or a small office (under 30% of the home), the actual-expense method can yield bigger deductions. This calculator shows both so you can compare your specific situation.

What counts as 'annual home running costs'?

Include mortgage interest (not principal), property tax, utilities (gas, electric, water), home insurance, and reasonable maintenance/repairs. Do NOT include capital improvements (new roof, new kitchen). The calculator apportions these by your office percentage to find the deductible amount.

Can anyone claim a home office deduction?

US W-2 employees generally cannot (IRS limits it to self-employed and business owners, with rare exceptions). UK and Canada are more flexible but require it to be your principal place of business. This calculator gives you the numbers, but you must verify eligibility for your tax code before claiming. Speak to a tax professional.

Last reviewed: June 20, 2026