Home Office Deduction Calculator

If you work from home, you can deduct a portion of your housing costs as business expenses. GigBooks includes a calculator to determine your percentage.

How it works

The CRA allows you to deduct home expenses based on the percentage of your home used for business. GigBooks calculates this two ways:

Room calculator

Add each room in your home with its dimensions (width × length). Mark which room is your office. GigBooks calculates:

• Total home square footage
• Office square footage
• Percentage = office ÷ total

Manual entry

If you already know your percentage, enter it directly.

What you can deduct

With your home office percentage, these expenses become partially deductible:

• Rent (if renting)
• Mortgage interest (not principal)
• Property tax
• Home insurance
• Utilities (electricity, gas, water)
• Internet
• Home maintenance and repairs

Important CRA rules

• Home office expenses cannot create a business loss — they can only reduce income to zero
• Unused amounts carry forward to the next year
• Never claim CCA (depreciation) on your home — this can disqualify your principal residence exemption when you sell
• You must use the space regularly and exclusively for business, OR it must be where you mainly (>50%) earn your income

Tips

• A percentage above 50% may trigger CRA scrutiny — make sure it's accurate
• Keep photos of your home office for your records
• The calculator is in Business Settings → Home Office