Simplified vs Regular Method Calculator
☆$5 per sq ft, capped at $1,500 — or your actual home expenses prorated by the office's share of the house. Run both numbers in a minute; the tool recommends the higher. (Self-employed / Schedule C filers only — W-2 employees see the Eligibility Checker first.)
Your inputs are saved on this device
The room's measured floor area — keep it under 300 sq ft for the simplified cap to matter.
Your whole residence — used to compute the office's share (area %).
Enter the full annual total; the tool prorates by area % automatically.
A common confusion: fill in the full-year totals, not your work-only guess — prorate happens in the math below.
California does not conform to the federal simplified method — the state return uses the actual method (FTB guidance via Calculus Tax).
Advanced ▾
Default 12. Moved mid-year? Use the Hybrid Proration Calculator for the two-location split.
Both methods, side by side
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Your area share
Why this matters
Once a self-employed worker has passed the eligibility and exclusive-use gates, the next question is arithmetic: simplified or regular? The IRS simplified method is deliberately simple — $5 per square foot of home-office space, capped at 300 square feet, so the maximum deduction is $1,500 a year, and per IRS guidance it is not adjusted for inflation (AI Nexis Lab aggregation). The regular method is the other way around: take your total home expenses — rent or mortgage, utilities, internet, insurance — multiply by the office's share of the home, and that is your deduction. The frequently asked question in Intuit community threads is whether to type the utility bill total or a work-only estimate: the answer is the full-year total, because the prorate by area% (and by months, if you moved) does the splitting. California adds a twist: FTB guidance cited by Calculus Tax says the state does not conform to the federal simplified method, so California filers run the actual method for the state return even when using simplified federally.
How it works
Enter office area, home area, annual rent/mortgage, and annual utilities + internet + insurance. The simplified line computes $5 × office sq ft, capped at $1,500. The regular line computes (rent + utilities) × area share × months fraction. The higher line is your recommendation — the tool does not tell you to claim the lower one. The Advanced months field handles partial years; a mid-year move to a new home office goes through the Hybrid Proration Calculator, which splits two locations by month × area × use.
What the results mean
If regular wins, keep the paper trail — 12 months of utility bills, the lease or mortgage statement, the insurance declaration page — because a correspondence audit will ask for them. If simplified wins, congratulations: the method exists precisely to skip that record-keeping, and the trade-off is the $1,500 ceiling. Either way, the comparison is an education estimate, not a filing conclusion; your CPA confirms the numbers against current-year IRS rules before you file.
Frequently Asked Questions
What is the simplified method for home office?
The IRS simplified method deducts $5 per square foot of home-office space, up to 300 square feet — a $1,500 annual maximum. It is not inflation-adjusted (IRS simplified-method guidance). It trades record-keeping for a low ceiling.
Should I use simplified or regular method?
Run both: simplified is $5 × office sq ft capped at $1,500; regular is total home expenses times the office's share of the home. This calculator compares them and recommends the higher — that is the method you may be eligible to use.
Does California allow the simplified method?
California state tax does not conform to the federal simplified method — if you file a California return, the actual (regular) method must be used for the state deduction, per FTB guidance cited by Calculus Tax. Use simplified federally and regular for California.