Methodology

Hourly rate

(take-home + expenses) / (1 - tax%) / ((52 - weeks off) x billable hours per week)

Self-employment tax set-aside (US)

profit x 0.9235 x 0.153 + profit x federal% + profit x state%. Ignores deductions, credits, the Social Security wage cap and the deduction for half of self-employment tax, so it is conservative. Verify with IRS.gov.

Retainer

hours x rate x (1 + premium%). Effective rate divides the retainer by delivered plus admin hours.

Limits

Results are estimates for planning, not advice.