WClockストップウォッチ
経過時間とラップを記録し、結果を書き出せます。
準備完了 · 時間 : 分 : 秒
スペース：開始・停止 · L：ラップ · R：停止中にリセット
ラップタイム
| ラップ | ラップ時間 | 合計時間 |
|---|
ラップがここに表示されます。始めましょう。
計測時間とラップはこのブラウザーに保存されます。ページを閉じても続きから再開できます。
Measure elapsed time and compare laps
A stopwatch counts upward from zero. Use it when you want to measure how long an activity takes, such as a practice presentation, a workout interval, or a repeated task. Lap records help compare individual segments within one session.
How to use this tool
- Start the stopwatch when your activity begins. Choose a display precision suitable for your task.
- Record a lap at each checkpoint to keep both the segment time and the total elapsed time.
- Pause when you finish, resume if needed, and export the lap table as CSV before clearing results you want to keep.
A practical example
Record a lap after each section of a rehearsal. A section’s lap time shows how long that section took; its total time shows how far into the full presentation it ended.
Common questions
What is the difference between lap time and total time?
Lap time measures the interval since the previous lap, or since the start for the first lap. Total time measures all elapsed running time up to that checkpoint.
Does showing milliseconds guarantee that accuracy?
No. Display precision is how many digits you see. Actual measurement also depends on browser scheduling, the device clock, and how quickly you press the controls. This is a practical browser stopwatch, not certified timing equipment.