SelfQuarter 1099 Tax

SelfQuarter estimates the quarterly federal tax a self-employed person owes on Schedule C income, the number that goes on Form 1040-ES. You enter your net self-employment income, last year's total tax, last year's AGI and any W-2 withholding, and the estimate updates as you type.

It is built for the single filer with Schedule C income: freelancers, contractors, consultants, gig workers and sole proprietors who send in four payments a year instead of having tax withheld from a paycheck.

WHAT YOU CAN DO
- Get a recommended quarterly payment, taken as the higher of your computed quarter and your prior-year safe harbor quarter
- Read the SE tax line by line: earnings at 92.35% of net, Social Security at 12.4% up to a wage-base cap, Medicare at 2.9%, and the extra 0.9% above $200,000
- See the deductions applied: half of your SE tax, then a simplified 20% QBI deduction that phases out at higher taxable incomes
- Run federal income tax through single-filer brackets, 10% to 37%, after a standard deduction
- Add an optional approximate state tax for 19 states, one flat rate per state, or leave it off
- Subtract W-2 withholding from a side job so the quarterly figure is what you still owe
- Check the safe harbor floor, 100% of last year's tax or 110% when your prior AGI was above $150,000
- Save a scenario, pin the ones you compare against, delete the rest
- Share a plain text breakdown from the share sheet

WHO IT IS FOR
- 1099 freelancers, contractors and consultants filing one Schedule C
- Sole proprietors and single-member LLCs paying estimated tax four times a year
- Anyone who wants a working number before sitting down with a CPA

WHAT IT DOES NOT MODEL
Itemized deductions, SEP and Solo 401(k) contributions, HSA, married filing jointly, dependent credits, AMT and NIIT sit outside the calculation. The About screen lists the main rates and thresholds the estimate uses, and what it ignores.

PRIVACY
No account, no sign-up, no server. Everything you type stays on your device, saved scenarios included, and it works with no connection. No ads, no tracking, nothing collected.

Runs on iPhone and iPad, in light and dark.

SelfQuarter gives you an estimate for planning. It is not tax advice and it is not affiliated with the IRS or any revenue agency. Confirm your final numbers with a CPA or a qualified tax preparer.