Free Fitness Tool
Workout
Timer
A powerful free interval timer for Tabata, HIIT, EMOM, boxing rounds and custom workouts. Set your work time, rest time, rounds and go — no account required.
✓100% Free
✓Audio Alerts
✓4 Presets
✓Works Offline
Work (sec)
Rest (sec)
Rounds
Prepare (sec)
Ready
00:20
Round 1 of 8
What Is Interval Training & Why Use a Timer?
Interval training alternates between periods of high-intensity effort and lower-intensity recovery (or rest). This training method is consistently shown to be one of the most time-efficient and effective approaches for improving cardiovascular fitness, burning calories and building endurance.
A dedicated workout timer removes the distraction of watching the clock during training, letting you focus entirely on effort and form. It also ensures you stick to your programmed work-to-rest ratios — one of the most important variables in interval training.
Timer Presets Explained
⚡ Tabata
20s Work / 10s Rest × 8 Rounds = 4 Minutes
The original high-intensity protocol developed by Dr. Izumi Tabata. Deceptively brutal — the 10-second rest is barely enough to recover before the next effort. Best for experienced athletes chasing maximum calorie burn and cardiovascular adaptation.
🔥 HIIT
30s Work / 30s Rest × Rounds
A 1:1 work-to-rest ratio makes this accessible for most fitness levels. The equal rest period allows near-full recovery between efforts, enabling you to maintain intensity across all rounds. Great for beginners to intermediate trainees.
⏱ EMOM
Every Minute On the Minute
Complete a set number of reps within each minute, then rest for the remainder of that minute. The faster you complete the work, the more rest you earn. EMOM builds strength endurance and is a staple of CrossFit and functional fitness programming.
🥊 Boxing
3 min Work / 1 min Rest × Rounds
Standard competition boxing round timing. Also excellent for general conditioning, heavy bag work, shadow boxing or any circuit training where you want sustained effort with meaningful recovery. A 3:1 work-to-rest ratio builds serious aerobic fitness.
The Science of Work-to-Rest Ratios
The ratio between your work period and rest period is the single most important programming variable in interval training. Here’s how to choose the right ratio for your goal:
- 1:4 ratio (e.g. 15s work / 60s rest): Maximises power output — used in true sprinting and explosive strength training. Full recovery between efforts.
- 1:2 ratio (e.g. 20s work / 40s rest): Balances power and metabolic conditioning. Good for high-intensity movements like kettlebell swings or box jumps.
- 1:1 ratio (e.g. 30s work / 30s rest): Classic HIIT ratio. Moderate intensity becomes challenging over multiple rounds as rest becomes insufficient for full recovery.
- 2:1 ratio (e.g. 40s work / 20s rest): Demanding — builds muscular endurance and cardiovascular capacity. Better suited to experienced trainees.
- Tabata (2:1): Technically a 2:1 ratio but at maximum effort, making it significantly harder than standard 2:1 intervals.
How to Get the Most from Interval Training
- Warm up properly. 5–10 minutes of progressive cardio and dynamic stretching before any interval session reduces injury risk and improves performance.
- Work at the right intensity. Work periods should be genuinely challenging — aim for 8–9 out of 10 perceived exertion. If you’re not breathing hard, you’re not working hard enough.
- Prioritise form over speed. Fatigue compromises technique. If your form breaks down, reduce intensity rather than risking injury.
- Progress gradually. Add one or two rounds per week, or reduce rest periods by 5 seconds — not both simultaneously.
- Allow recovery time. 2–3 HIIT sessions per week is typically the maximum for most people. Overdoing intensity without adequate recovery leads to overtraining.
- Use audio cues. Our timer includes sound alerts so you can keep your eyes on your form, not the screen.
⚠ Safety Note
High-intensity interval training places significant demand on the cardiovascular system. If you are new to exercise, have a heart condition, or any health concern, consult your doctor before starting HIIT training.
Frequently Asked Questions
Workout Timer FAQ
What is Tabata training?
Tabata is a high-intensity interval training protocol developed by Japanese scientist Dr. Izumi Tabata. It consists of 8 rounds of 20 seconds maximum effort followed by 10 seconds rest, totalling 4 minutes. Research shows it improves both aerobic and anaerobic capacity more efficiently than moderate-intensity steady-state cardio.
How many calories does HIIT burn?
Calorie burn varies significantly based on body weight, fitness level, and effort intensity. A 75kg person doing vigorous HIIT can burn 300–500 calories per 30-minute session. HIIT also elevates metabolism for several hours post-workout (the “afterburn” effect), increasing total daily calorie expenditure.
What does EMOM mean?
EMOM stands for “Every Minute On the Minute.” At the start of each minute, you perform a prescribed number of reps of an exercise. The remaining time in that minute is your rest. EMOM workouts are great for building work capacity, practising skill-based movements, and maintaining intensity across a longer session.
How often should I do interval training?
For most people, 2–3 HIIT sessions per week is optimal. High-intensity training is demanding on the nervous system and muscles and requires adequate recovery. Combining 2 interval sessions with 2–3 strength sessions and some steady-state cardio or active recovery is a well-rounded weekly programme.
Can beginners use this workout timer?
Yes — use the custom settings to set longer rest periods and shorter work intervals as a beginner. A 20s work / 40s rest ratio is a sensible starting point. As fitness improves, gradually reduce rest time or increase work time. Always start with lower intensity movements and prioritise form over speed.
Does this timer work without an internet connection?
Once the page is loaded, the timer runs entirely in your browser and does not require an internet connection. The audio alerts use the Web Audio API which is built into modern browsers. You can keep the tab open at the gym without worrying about losing connection.