A bill rate calculator answers one question: what does an hour of this person's time have to bill at for the firm to make the margin it wants? The arithmetic is short and the mistakes are consistent, which is why it is worth setting out step by step rather than trusting a rule of thumb. Every input is the firm's own figure, and the two that move the answer most, the billable hours and the way the margin is applied, are the two most often guessed. This page works the method; the free billable rate calculator on this site works it live from your own numbers, with no account.
Step one: load the salary
Start with the annual salary, then add the employer burden: payroll taxes, benefits, insurance and paid time off, as a percentage of salary taken from the firm's own payroll figures rather than a published average. Then add the share of firm overhead this person carries, which is rent, software, administrative staff, licences and the partner time that is never charged to a client, divided across the chargeable staff. The result is what the person costs the firm for a year, and it is usually a good deal more than the salary suggests.
Step two: divide by the hours that actually bill
The loaded cost has to be recovered from the hours that reach an invoice, not from the hours the person is paid for. Training, internal meetings, business development, the quiet weeks and the write-offs all come out first. A firm that budgets on paid hours and bills a fifth fewer has priced every hour a fifth too low, and the shortfall arrives as a margin that never appears. Use last year's time records if you have them; if you do not, the measured figure from one honest quarter beats any assumption.
Step three: apply the margin as a margin, not a markup
The bill rate that leaves a margin of thirty percent is the cost per billable hour divided by one minus thirty percent, not the cost multiplied by one point three. On a cost of $90.36 an hour the first gives $129.08 and the second gives $117.47, and the difference is the whole of the firm's profit on that hour being understated by a third. This is the arithmetic most often got wrong in a firm's rate card, and once it is wrong on one grade it is usually wrong on all of them.
From the bill rate to the fee
The bill rate is the standard rate for a grade. A fee for an engagement blends the partner, manager and staff hours at their standard rates into one rate, then applies the realization the firm actually achieves, and that realized figure is what a fixed fee should be quoted against. The blended rate calculator on this site works that second step; the paid plan keeps the resulting fee on the client record so that next year's review starts from what was really charged and really worked.
Questions people ask about bill rate calculator
Should the bill rate include partner time?
Partner time that is charged to clients has its own rate. Partner time that is not, on management, review of the firm's own affairs and business development, belongs in overhead, where it is recovered across every chargeable hour.
What if the person bills more hours than budgeted?
Then the rate recovers the cost early and the extra hours are margin. The danger runs the other way: a rate set on hours that never arrive leaves the cost unrecovered, which is why the billable hours input should be the measured figure.
Is the bill rate the same as the rate on the invoice?
It is the standard rate. What the invoice shows is that rate after realization, discounts and write-offs, which is why the blended rate worksheet asks for the realization the firm actually achieves.