Plank timer
Online plank timer with 30s, 1, 2, and 5 minute targets, progress bar, and best-hold tracking.
Open toolTools
Free fitness tools that run in your browser.
No signup, no install. Time a plank, count push-ups, or work out your daily calorie and water needs right here — and when you want automatic tracking, streaks, and Apple Health sync, the BigBeeFit apps pick up where the browser leaves off.
Timers
Countdowns and interval timers for holds, HIIT sessions, and rest between sets.
HIIT & Tabata timer
Interval timer with work/rest phases, rounds, and audio cues — Tabata, 30/30, and 40/20 presets included.
Open toolWall sit timer
Timed wall sits with 30-second to 3-minute targets, best-hold tracking, and form checkpoints.
Open toolStretch timer
Simple timer to pace your stretching routines.
Open toolRest timer
Presets to time your rest between sets perfectly.
Open toolCounters
Tap counters for reps and sets — no pen, no mental math.
Calculators
Your daily numbers: calories, BMI, heart rate zones, pace, hydration, and more.
Water intake calculator
Calculate how much water to drink a day based on your weight and activity level — in liters, glasses, and ounces.
Open toolBMI calculator
Body mass index with WHO category and the healthy weight range for your height — metric and imperial.
Open toolHeart rate zone calculator
Max heart rate and all 5 training zones from your age, with the Karvonen option for resting HR.
Open toolRunning pace calculator
Pace per km and mile from distance and time, plus finish-time projections for 5K to marathon.
Open toolTDEE calculator
Daily calorie needs from the Mifflin-St Jeor formula, with lose, maintain, and gain targets.
Open toolCalories burned
Estimate energy burned from your favorite activities.
Open toolBody fat calculator
Estimate your body fat percentage quickly.
Open toolMacro calculator
Split your calories into protein, carbs, and fat.
Open tool1RM calculator
Estimate your one-rep max safely.
Open toolSleep calculator
Find the best time to sleep or wake up.
Open toolConverters
Turn one unit into another: steps to distance, laps to kilometers and calories.
Challenges
Day-by-day challenge tables you can check off right in the browser.
Looking for something specific?
Browse our apps to find the right tool, or reach out — we're happy to point you in the right direction.