Your computer does not qualify for Section 179 for 2021 since you used it personally for the majority of the year and did not place it into service until November. this prevents someone from using it for the majority of the year for personal purposes and then adding it as an asset at the end of the year. You did not fully convert the property to business use. You are continuing to use it for personal use.
Since you placed it in service in the last quarter of the year, you must use the midquarter convention. In future years, you can depreciate the business percentage as usual. Percentages can change from year to year.
Partial business use.
When you use property for both business and non-business purposes, you can elect the section 179 deduction only if you use the property more than 50% for business in the year you place it in service. If you use the property more than 50% for business, multiply the cost of the property by the percentage of business use. Use the resulting business cost to figure your section 179 deduction. PUB 946
Example.
May Oak bought and placed in service an item of section 179 property costing $11,000. She used the property 80% for her business and 20% for personal purposes. The business part of the cost of the property is $8,800 (80% × $11,000).
