Hours Calculator

How does it work?

In Add/Subtract mode, the tool works on two times in HH:MM format. Under Worked time, it takes exit minus entry and also discounts the lunch break.

The result shows up as hours:minutes and also as a decimal, that second form being handy when you multiply by an hourly rate.

Everything runs 100% in your browser.

How time arithmetic actually works

Adding and subtracting hours is not decimal arithmetic — it is base-60 (sexagesimal) for minutes and seconds, base-24 for hours within a day. The reliable algorithm: convert each time to total minutes (or seconds) with total = h × 60 + m, perform the sum or subtraction on the integer total, then convert back with h = total ÷ 60 and m = total mod 60. For seconds, use 3600 as the divisor. This avoids the classic bug of "08:45 + 00:30 = 08:75".

Worked-day calculation uses worked = exit − entry − break. Concrete example: entry 08:00, exit 17:30, break 01:00 → worked = 17:30 − 08:00 − 01:00 = 08:30 (8h30 or 8.5 decimal hours). When the exit crosses midnight (night shift), add 24h to the exit before subtracting: an entry at 22:00 and exit at 06:00 becomes (06 + 24) − 22 = 08:00.

Brazilian working hours under the CLT

The Consolidação das Leis do Trabalho (CLT) caps standard hours at 8 hours per day and 44 hours per week (art. 58), with up to 2 hours of overtime allowed per day. A mandatory intra-day rest of 1 to 2 hours applies to shifts above 6 hours (art. 71), and a minimum 11-hour rest is required between two shifts. The labor reform (Lei 13.467/2017) created the banco de horas, letting employers offset extra hours within 6 months by individual agreement, or 1 year by collective agreement.

FAQ

How do I convert hours to decimal? Divide the minutes by 60 and add to the hours: 8h45 becomes 8 + 45/60 = 8.75. This is the format payroll software uses to multiply by hourly rate.

Do I include the lunch break in worked hours? No. The intra-day break (intervalo intrajornada) is not paid time under standard CLT contracts — it is subtracted from the total between entry and exit.

What is DSR and how does it affect my paycheck? The Descanso Semanal Remunerado is one paid rest day per week, usually Sunday. If you receive overtime or commissions, the DSR must be recalculated to include them, otherwise the employer owes a "reflexo no DSR" adjustment.

Can the result be negative? Yes — when subtracting a larger time from a smaller one. This calculator shows the absolute difference; check the order of inputs if the result is unexpected.