If the home office is your only workplace, the percentage would be 100% However, if there are other fixed locations where you perform your work, you will need to allocate the percentage by the time worked in the home office versus the time working elsewhere.
See the following from IRS Publication 587:
More than one place of business.
If part of the gross income from your trade or business is from the business use of part of your home and part is from a place other than your home, you must determine the part of your gross income from the business use of your home before you figure the deduction limit. In making this determination, consider the time you spend at each location, the business investment in each location, and any other relevant facts and circumstances.
If the home office is your only workplace, the percentage would be 100% However, if there are other fixed locations where you perform your work, you will need to allocate the percentage by the time worked in the home office versus the time working elsewhere.
See the following from IRS Publication 587:
More than one place of business.
If part of the gross income from your trade or business is from the business use of part of your home and part is from a place other than your home, you must determine the part of your gross income from the business use of your home before you figure the deduction limit. In making this determination, consider the time you spend at each location, the business investment in each location, and any other relevant facts and circumstances.