Can I write off a laptop if I use it half for business and half personal?

Generally, yes — but only the business-use portion is deductible.

If you use a laptop 50% for business and 50% personally, you would usually be able to deduct about 50% of the cost, assuming you’re otherwise allowed to claim business equipment expenses.

A few important caveats:

• If you’re self-employed or run a business, you can usually deduct the business-use share of a mixed-use laptop.
• If you’re a W-2 employee, federal deductibility of unreimbursed employee expenses is generally not available under current rules, so this often can’t be written off on your federal return.
• Section 179 generally requires the laptop to be used more than 50% for business, so if it’s only 50% business use, Section 179 usually is not available for the full cost.
• If the laptop is inexpensive enough, the de minimis safe harbor may let you expense it immediately if you meet the tax-rule requirements and the item falls under the applicable per-item threshold.

So, for a $1,000 laptop used half for business, the business deduction is often $500, but the exact tax treatment depends on your filing status, business structure, and which expense rule you use.

Keep records showing how you determined the business percentage, since the IRS can ask for support.