Free Online Fitness Timer — HIIT, Tabata & More

Fitness Timer — Interval & Workout Countdown
for Gym and Home

Display a fullscreen countdown on your gym TV or home screen. Control from your phone while you train.

WORKRESTFitness Timer

See the Timer While You Train

Most people use a phone stopwatch during workouts — glancing down at the last second, losing their exercise form, breaking focus. A fitness timer displayed on a TV or gym screen keeps the countdown visible from anywhere in the room, so you stay in position and keep moving.

Professional gym timer systems are often fixed programs that can't be customized. Castimer lets you display a custom workout timer on any screen — phone control, fullscreen display — freeing your attention completely.

When you can see a fullscreen workout timer without looking down, your form stays consistent, your reps stay clean, and your focus stays on the movement, not on your phone screen.

No looking down at your phone between sets

No breaking your exercise form

Timer visible from anywhere in the room

WORKRESTFitness Timer
ROUND 4/8Group Fitness Class

Cast the Timer to Your Gym TV or Home Screen

Open the viewer link on any screen — a wall-mounted gym TV, a living room television, or a tablet propped on your equipment. Castimer makes it simple to cast your workout timer to the gym TV with a clear, high-contrast countdown that's visible from every angle.

Control start, pause, and reset from your phone without walking back to the screen. Whether your setup uses Chromecast, AirPlay, or HDMI, Castimer adapts to your space.

For a detailed guide on each casting method, see our full casting guide.

Wall-mounted gym TV with Chromecast or AirPlay

Living room TV via HDMI for zero-latency display

Tablet propped on exercise equipment

Extend desktop mode on a secondary monitor

Workout Formats That Use a Fitness Timer

A workout timer isn't one-size-fits-all. Here are the most common training formats where a visible countdown makes a real difference.

HIIT (High-Intensity Interval Training)

Set your work interval and rest interval, then let the HIIT timer cycle through them automatically. Audio alerts signal each transition so you know when to push and when to recover — no need to stare at the screen.

Circuit Training Rounds

Each station gets a different duration. A circuit timer helps you move through exercises in sequence, keeping your heart rate up and your rest periods tight.

Tabata Intervals (20 sec on / 10 sec off)

20 seconds of all-out effort, 10 seconds of rest, repeated 8 times. A precise Tabata timer is essential — manual timing or counting out loud simply isn't accurate enough for this intensity level.

AMRAP and EMOM Formats

As Many Reps As Possible or Every Minute on the Minute — these formats demand strict time boundaries. A visible interval timer keeps you honest about when each round starts and ends.

Rest Period Countdowns Between Sets

30-90 seconds between sets. A rest timer for workout sessions prevents you from resting too long (losing momentum) or too short (not recovering enough). Set it and forget it.

Warm-up and Cool-down Timers

5-10 minutes before and after your workout. A dedicated workout timer ensures you spend enough time warming up muscles and cooling down afterward — the most neglected parts of any routine.

How to Set Up Your Workout Timer

Three simple steps to add a fitness timer to your next training session.

Set your work interval and rest interval

Go to the timer page and set the duration for your work period and rest period. Choose a theme that works well on a big screen. Set as many rounds as your workout requires.

Create Timer

Open the viewer on your TV or display screen

Open the viewer link on your gym TV, living room screen, or tablet. The countdown fills the display with large, clear numbers visible from any angle.

Open Viewer

Start the timer from your phone and begin training

Hit start from your phone and begin your workout. Pause if you need extra rest. Reset between sessions. The screen updates in real time.

Works for These Training Environments

Whether you're training at home, in a commercial gym, or leading a group class — Castimer adapts to your space.

Home Gym — Cast to Your Living Room TV

A home gym timer that uses your existing TV. No need to buy expensive equipment. Simply cast the viewer to your living room screen and start training.

Commercial Gym — Display on a Wall-mounted Screen

A gym timer on the wall-mounted display in the free weights area. Everyone passing by can see the countdown. Perfect for circuit stations.

Group Fitness Classes — Visible to the Whole Room

A group fitness timer projects to the front of the room. The entire class stays synchronized — clearer than the instructor calling out time, and fewer “how much longer?” questions.

Outdoor Training — Open on a Tablet or Large Phone

For outdoor bootcamps and park workouts, open the timer on a tablet or large phone. The big numbers are visible even in bright sunlight.

Personal Training Sessions — Control for Your Client

The trainer controls the timer while the client focuses on the screen. No need to sync watches or guess — it looks more professional and saves communication time.

Why Castimer for Fitness

Completely free, no app download required, no registration needed. Whether it's a quick 10-minute HIIT session, a 45-minute circuit training, or a full Tabata workout — set up your fitness timer in seconds.

Every fitness level can benefit from better time management. From beginner home workouts to advanced CrossFit sessions, Castimer adapts to your routine.

The fullscreen workout timer works on all major browsers — Chrome, Safari, Edge, Firefox. No special software needed.

No app download required

Fullscreen display, large enough to see across the room

Free to use — unlimited sessions

Audio alerts at interval switches

No limit on rounds or cycles

20s WORK3/8TABATA

Frequently Asked Questions

Quick answers about using Castimer as a fitness timer.

Can I set different work and rest intervals?

Yes — set any work duration and rest duration independently. The timer cycles through them automatically.

Does the timer make a sound when the interval switches?

Yes, an audio alert plays at the end of each interval so you know to switch without looking at the screen.

Can I use this for Tabata training?

Yes. Set 20 seconds work and 10 seconds rest, choose 8 rounds, and the timer handles the entire Tabata sequence.

How do I display the timer on my gym TV?

Open the viewer link in Chrome and use the Cast button to send it to a Chromecast-connected TV. Or connect via HDMI and go fullscreen. For detailed instructions, see our casting guide.

Is there a limit on how many rounds I can set?

No limit — set as many rounds as your workout requires.

Ready to Upgrade Your Workout Timer?

Free. No signup. Works with your TV, phone, or tablet.