Get a cold as an employee and your paycheck doesn't notice — most companies keep paying you while you rest. Get a cold as a freelancer and your income drops to zero for every day you can't work, on top of whatever bills keep arriving regardless. Most freelancers never price for this; they just absorb the hit when it happens and hope it doesn't happen often. This calculator turns "hope" into a number, showing exactly how much to load onto your day rate so a realistic run of sick days is already funded before you ever catch one.
How it works
The calculator starts by pricing what your expected sick days actually cost: your day rate multiplied by the number of sick days you expect in a year. That's money you won't invoice for reasons entirely outside client scope — not a discount, not a slow month, just days you physically can't work.
Then it works out how to recover that money without billing more days than you have. It takes your billable days per year and subtracts your expected sick days, leaving your working billable days — the days you'll actually be healthy enough to invoice. Dividing expected sick days by working billable days, and converting to a percentage, gives you the rate loading: the percentage bump your day rate needs so that your healthy days alone cover the income your sick days would have earned. Apply that percentage to your day rate and you get your adjusted day rate — the number to actually quote clients.
The logic mirrors how insurers price risk: spread a predictable-but-uncertain cost across every unit sold, rather than letting it land as a surprise on whichever day it happens to hit. You're insuring yourself, and the "premium" is a small, permanent bump to your rate.
Worked example
Say your day rate is $400, you expect 6 sick days in a typical year, and you have 220 billable days per year when healthy.
- Annual income at risk: $400 × 6 = $2,400
- Working billable days: 220 − 6 = 214
- Rate loading needed: (6 ÷ 214) × 100 = 2.8037...% → rounded to 2.8%
- Adjusted day rate: $400 × (1 + 2.80 ÷ 100) = $400 × 1.028 = $411.20
Quoting $411.20 instead of $400 across your 214 healthy working days brings in roughly the same total annual revenue you'd get from 220 days at the unadjusted $400 rate — the loading on your healthy days replaces the income the 6 sick days would otherwise have cost you.
How to interpret your result
The rate loading percentage is the headline number: it's the permanent bump your day rate needs to carry so illness stops being a silent tax on your income. It's deliberately small for most freelancers — a handful of sick days spread across two hundred-plus billable days rarely pushes past low single digits — which is exactly why it's easy to skip pricing for and easy to actually absorb once you do.
The annual income at risk figure shows the raw exposure in dollar terms: what you stand to lose in a typical year if you don't load your rate at all and simply eat each sick day as it comes. Compare it to what you currently have set aside for exactly this scenario — if the answer is nothing, that gap is exactly what the adjusted day rate is meant to close going forward.
The adjusted day rate is the number to actually use. Whether you quote it directly to new clients or phase it in at your next renewal, it's built so your healthy days alone recover what your sick days cost, without requiring you to work more hours or chase more clients to make up the difference.
This is deliberately distinct from planning a vacation: a trip is scheduled, so you can save toward it in advance with a monthly target. A sick day isn't scheduled — it shows up uninvited, on a Tuesday, with a deadline still due. That unpredictability is exactly why the fix here is a permanent rate loading rather than a savings plan you might not have funded yet when illness actually strikes.
Methodology & sources
The formula: annualLostIncome = dayRate × expectedSickDaysPerYear, workingBillableDays = billableDaysPerYear − expectedSickDaysPerYear, rateLoadingPercent = (expectedSickDaysPerYear ÷ workingBillableDays) × 100, and adjustedDayRate = dayRate × (1 + rateLoadingPercent ÷ 100). Every figure is rounded to two decimal places for display, and the adjusted day rate is calculated from the displayed loading percentage so the two numbers reconcile exactly if you check the math by hand.
This isn't a theoretical problem. The U.S. Bureau of Labor Statistics tracks access to paid sick leave across the civilian workforce and explicitly excludes the self-employed from that benefit entirely — freelancers aren't a small underserved slice of the paid-sick-leave picture, they're outside it by definition. Pricing your own sick-day buffer isn't optional financial planning; for a freelancer, it's the only version of paid sick leave that exists.