40 Minute Timer

The page loads with 40 in the Minutes box and 0 in the other two, which is 2,400 seconds. The clock reads 40:00, so for most jobs there is nothing to set up.

1. Look at Quick start. It has entries for 25, 30 and 45 minutes but none for 40, so it shows Custom time while the three boxes below already hold your 40 minutes.
2. Check Hours (0), Minutes (40) and Seconds (0). Change them if you want a slightly different length, such as 37 minutes 30 seconds, and the clock updates at once.
3. Add a Label (optional) such as Period 3 or Section B. It sits above the digits and appears again in the message at zero.
4. Keep Play a sound when time is up ticked for the four-tone alarm, or untick it for a silent countdown.
5. Press Start. Use Pause and Resume for interruptions, Reset to return to 40:00, and Full screen to show a large clock to a room.

Space starts and pauses, and R resets while the timer is stopped, as long as the cursor is not inside a text box.

Forty minutes is a common length for a school lesson, a college tutorial and one section of a longer exam. It is long enough to cover a topic properly and short enough that attention does not drift too far. In numbers, it is 2,400 seconds, two thirds of an hour, or 0.67 in decimal hours.

A teacher with a 40 minute period might divide it like this, with the time the clock should show when each part ends:

The progress bar gives a second cue. Each minute is 2.5 percent of its width, so when it is half full exactly 20 minutes remain, and students can see how much is left without asking.

Exam practice works the same way. Suppose a paper section has 25 questions and you want to keep 5 minutes for checking. That leaves 35 minutes, which is 2,100 seconds, and 2,100 divided by 25 is 84 seconds per question. If you are stuck at 84 seconds, move on and come back. The time calculator is handy for adjusting a plan like this when the numbers change.

In the kitchen, a cake or a tray of roast vegetables often needs about 40 minutes. Ovens differ, so many cooks set a first alarm a few minutes early, check with a skewer or a fork, and then restart the timer for a short extra period. Follow the recipe and the food itself rather than the clock alone.

The countdown rings once and then stops. It does not repeat, you cannot run two timers side by side, and nothing is saved when you close the page. If you want work and rest to alternate on their own, the Pomodoro timer chains focus sessions and breaks for you.

• Page must stay open. Closing the tab ends the count, and a phone that locks its screen may pause the page and silence the alarm. For anything important, add a second alarm on the phone itself.
• Not a Pomodoro length. The classic Pomodoro is 25 minutes of focus with a 5 minute break. Forty minutes is closer to two 20 minute halves with a stretch in the middle, which you can run by setting the boxes to 20 minutes twice.
• Shorter or longer. If a lesson period is 30 minutes, the 30 minute timer is already set. For a 45 minute class, use the 45 minute timer.
• Finding out how long a task really takes. Run the online stopwatch once, then come back here and set the countdown to match.

The clock is compared with your device time instead of counting ticks, so a tab that the browser slows down while hidden still shows the right time when you return. The sound itself can arrive a little late in that case, so keep the tab visible when the exact moment matters. On devices that support it, the page also asks the screen to stay awake while the timer runs, which helps when the clock is propped up on a desk.

Changing the Label box while the timer is paused does not reset the time, so you can rename a block between rounds without losing your place.