How can my whole house be 260 sq feet but one room in the house is a 100 sq feet? I’m trying to calculate my home office but it doesn’t make sense that my office is 10x10 and my whole house

I’m approaching this question assuming that your home office pertains to self-employment.

It sounds like a typo is the culprit here. May I recommend that you review your square footage entries? Here’s how to do this in TurboTax Online:

1. Under Income & Expenses (tab at the top of your screen), click Review next to Self-employment income and expenses (this assumes that you have already entered your self-employed income).
2. Click Review again next to the specific self-employed activity and scroll down to the Expenses category.
3. Click Review next to Home office.
4. Proceed through the interview until you get to the page that says: What was the size of this home office. Double check your entries here.  

Looks to me like you made a type and incorrectly entered 260 when  you should have entered 2600. That would be the expected square footage of a 4 bedroom house with 2 or 3 full baths and a 2 or 3 car garage.