Overtime Pay vs Free Time Logic

Is Overtime Worth It?

The gross rate is the number on the offer, and it is not the number that reaches you. Extra income is taxed at the marginal rate rather than an average one, so the hourly figure shrinks before anything else is considered. Then the hours themselves have a price: whatever the time would otherwise have been worth. This calculator sets the after-tax earnings against that second figure and returns the difference, which can land either side of zero.

The Diminishing Returns of Hours Worked

Worth saying plainly: this model has no diminishing returns in it. Hours enter as a straight multiplier on both sides, so ten hours at the defaults returns minus 50 and forty hours returns minus 200, exactly four times as much. The verdict never changes with volume. Whether overtime pays is settled entirely by the other three inputs, and the hours only scale the size of the answer.

That is a simplification rather than a claim about how people work. Fatigue, the quality of the following day's output and the recovery a long week needs are all real and none of them is in here. Anyone who thinks the tenth extra hour is worth less than the first can represent that by raising the free time value, which is the field the model gives for exactly that purpose.

What Does Your Free Time Actually Cost?

Free time is not empty time. It is when rest happens, relationships get maintained, and whatever else the week needs gets done. Putting a number on it feels artificial, and it is, but the alternative is leaving it at zero, which is a stronger claim than any figure you might pick. One workable approach is to ask what you would willingly pay to get an hour of the day back: the going rate for cleaning, childcare or delivery is a rough floor for that.

At the defaults the whole question turns on this one field. Net overtime is 15 an hour after tax, so a free time value below 15 leaves the month positive and anything above it does not. At 10 an hour the month returns plus 50; at 20 it returns minus 50; at exactly 15 it returns zero.

The Hidden Costs People Often Overlook

Tax is the visible one. Underneath it sit costs that never appear on a payslip: a meal bought rather than cooked, a later journey home, childcare stretched to cover the extra hours, and the quality of the next working day. None of these is an input here, and all of them push the same way, against the overtime. A result that is already close to zero tends to cross it once they are counted.

A worked example

With the defaults: overtime hourly rate of 25, marginal tax rate of 40, monthly overtime hours of 10, free time hourly value of 20. The tool returns -50.00.

The 25 an hour becomes 15 after 40% tax, so ten hours earns 150. The same ten hours of free time is valued at 200. The difference is minus 50, which is the month's answer: at these numbers the hours cost more than they pay.

What moves the number most

The result responds to Overtime Hourly Rate, Marginal Tax Rate, Monthly Overtime Hours, and Free Time Hourly Value.

Three of those decide the sign and one does not. The marginal tax rate is the sharpest of the three at this scale: holding everything else, a rate of 20% instead of 40% turns minus 50 into exactly zero, because it lifts the net hourly from 15 to 20 and meets the free time value head on. The gross rate would have to reach 33.33 an hour to do the same at a 40% rate, since that is where 60% of it meets the 20 the free time is worth. Hours, as above, only multiply.

The formula behind this

Net benefit is the after-tax overtime earnings minus the value of the time they consume. The gross hourly rate is reduced by the tax rate to give a net hourly figure, that is multiplied by the monthly hours to give after-tax income, and the hours multiplied by the free time value are subtracted from it. Written out: O × (1 − T ÷ 100) × H − F × H, which factors to H × (O(1 − T ÷ 100) − F), and the bracket is why the hours cannot change the sign.

The model applies one flat rate rather than working through tax bands, treats every overtime hour as worth the same as every other, and takes no account of opportunity costs beyond the free time figure entered. It is a framework for thinking rather than a payroll calculation.

When to revisit

The answer is not fixed, because none of the three deciding inputs is. A pay rise moves the gross rate, crossing a tax threshold moves the marginal rate, and the value of an hour at home moves with whatever else is happening in a life: a new child, a finished degree, a quieter stretch. A result of minus 50 a month is not a verdict on overtime, only on overtime at these four numbers.