Day rate vs real net: what the math hides
"My day rate is 500 euros, so I make 10,000 euros a month." That reasoning comes up often, and it's wrong in a way that costs money: it ignores the charges, which aren't a fixed percentage, but vary by a factor of two depending on the chosen legal status. I've already written about the method for setting your day rate. This article answers a different, narrower question: once the day rate is set, how much is actually left each month? That's the question TJM2Net answers, and the calculation hides more than it looks like.
A salaried job isn't simpler#
Before comparing freelance and salaried work, salaried work itself hides a variable that's often forgotten: manager status versus non-manager status changes the employee contribution rate. On a gross annual salary of 40,000 €, the status difference changes the final net, not just the label on the payslip.
Gross annual salary 40 000 €
− Employee contributions − 9 200 € (23%, non-manager status)
= Net annual before tax 30 800 €
÷ 12 months
= Net monthly before tax 2 567 €
The contribution rate changes with status, but the calculation's structure stays the same: annual gross, minus employee contributions, divided by twelve. It's this structure, not the exact rate, that needs to stay visible at every step rather than hidden inside a black-box formula.
Freelancing: four statuses, four different charge logics#
A freelance day rate never converts to net the same way across legal statuses. Four structures coexist, with fundamentally different charge logics:
| Status | Charge logic |
|---|---|
| Micro-entreprise (sole trader) | Flat contributions on revenue, simple but capped at an annual revenue ceiling |
| Umbrella company (portage salarial) | Management fees to the umbrella company, then standard employee contributions |
| SASU (single-shareholder company) | Social contributions under the assimilated-employee regime, dividends possible with distinct taxation |
| EURL (single-member LLC) | Self-employed contributions, generally lower but with different social protection |
An identical 500 € day rate produces a different net monthly income depending on which of these four statuses cashes it, with gaps that can exceed several hundred euros a month. Comparing two mission offers on their displayed day rate alone, without knowing the underlying status, means comparing numbers that don't measure the same thing.
The calculation, never hidden in a black box#
The design principle that matters most in TJM2Net isn't the accuracy of the rates, it's that every step of the calculation stays displayed at all times, never collapsed into a single final number. On a base of 210 billed days a year, the conversion always follows the same shape: day rate excluding tax × billed days, minus status-specific charges, divided by twelve. Hiding that sequence of steps behind a single result creates an illusion of precision the calculation doesn't have: the real contribution rates depend on the collective bargaining agreement, personal tax brackets, possible exemptions (ACRE for sole traders, for instance), all parameters a general-purpose simulator approximates rather than replaces an accountant for.
What this changes in practice#
The practical takeaway isn't a precise charge rate to remember, it's refusing to compare two incomes without running the conversion all the way to net. A 550 € day rate as a sole trader and a 500 € day rate through an umbrella company can land on the same net monthly income, or several hundred euros apart, depending on real ceilings and management fees. The number shown on a mission offer is never the number that counts: it's the one left after going, step by step, through the underlying status's charge structure.
