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Jump Measurement Guide: Capturing Lower-Body Power in the Field

  • Jul 3
  • 8 min read

The vertical jump is the most honest expression of lower-body power. Grabbing a rebound, driving a spike, rising for a contested ball in the air -- in that instant, how fast and how hard the legs extend shows through completely. That's why jump height has long been used as a benchmark of an athlete's ability.

The problem is that judging "how high did they jump" by eye alone leaves you leaning on gut feel. It's hard to tell at a glance whether an athlete is flat today, whether they've improved since last month, or whether the left and right legs differ. This article is about recording jumps as numbers and reading those numbers -- what values come out of a single jump, what they mean, and what you need to keep in mind to get data you can trust in the field.

What values do you get from a jump measurement

Back when you marked a wall and measured by hand, the only result was a single height. With a sensor, one jump gives you several values at once.

Value

What it tells you

Jump height (cm)

The headline indicator of lower-body extension power. The first number a coach looks at

Flight time (s)

The time from when the feet leave the ground until they touch down again. The value that jump height is built on

Takeoff velocity (m/s)

The speed at the instant of leaving the ground -- how fast the athlete drove the body up

Ground contact time (s)

In moves like the drop jump, where the athlete lands and immediately jumps again, the time spent on the ground. It feeds into reactive strength (RSI)

Grade

An automatic 5-level grade assigned against sex-specific standards

Calculating jump height from flight time is a standard method that has long been used in sports science (jump height = gravity × flight time² ÷ 8). PoinT GO captures the moments of takeoff, flight, and landing with a 9-axis IMU wearable sensor, and its own optimized proprietary algorithm computes these values automatically. PoinT GO handles which signals it uses and how it calculates them, so the coach can focus purely on putting the resulting numbers to work in the field.

One thing worth flagging. What a jump measurement gives you are movement values like height, time, and velocity. It does not directly measure the force pushing against the ground (N) the way a force plate does. That's why jump results are strong at showing exactly "how high and how fast someone jumped."

Different jump types reveal different abilities

Even the same "jump" reveals different abilities depending on how you do it. PoinT GO lets you pick the type and measure it.

  • Counter movement jump (CMJ): The most common and most reproducible jump, where the athlete dips slightly and rebounds upward. Unless you have a specific reason otherwise, starting with the CMJ alone is fine.

  • Squat jump (SJ): Jump from a squatting position after a brief pause, with no countermovement. It shows pure pushing strength. Measured alongside the CMJ, it lets you compare how well the athlete uses the rebound.

  • Abalakov: A CMJ with arm swing allowed. It shows jumping power that is closer to actual game movements.

  • Single-leg CMJ (left/right): Measures each leg separately. Essential when you want to see the difference between left and right.

  • Drop jump: Step off a box and jump again the instant you land. Ground contact time comes out with it, feeding into reactive strength (RSI).

Choose to fit the demands of your sport. If time is tight, the CMJ alone is enough; for basketball or volleyball where reactivity matters, add the drop jump; if left-right balance is a concern, add the single-leg CMJ.

Measuring jumps with PoinT GO

The flow for measuring a jump in the field is simple. Whether you use the app (connect) or the web (coach-web), the sequence is the same.

  1. Attach the sensor: Fasten the 15g PoinT GO sensor firmly to the top of the shoe (the instep) with the body strap (for single-leg measurement, on the instep of the leg being tested). Securing it so it doesn't shift directly affects accuracy.

  1. Select the jump type: Pick what you're measuring today from CMJ, squat jump, drop jump, and so on. For the drop jump, also set the box height.

  1. Get ready: Press "Ready" and stand still through a short countdown. In this still stance, the sensor sets its baseline.

  1. Measure: Jump with maximum effort on the signal. Everything from takeoff to landing is captured automatically, so height and flight time appear on screen the moment you jump.

  1. Save: Check the result and save it to the athlete's record.

PoinT GO automatically filters out botched attempts and ambiguous wobbles. Values that don't look like a proper jump aren't accepted as results, so the coach doesn't have to judge "redo that one" case by case.

Measuring with the connect app lets you test right there in the field with just a phone, and you can capture form with the camera at the same time. It's handy when you're cycling through athletes one after another.

How to read the results

Reading the values you measured is where it really counts. Just a few things to remember.

Look at a representative value across several attempts, not a single one. We're human, so every jump comes out a little different. PoinT GO gathers the attempts and shows you the best height, average height, and average of the top 3 together. For that day's benchmark, using the best height or the top-3 average is more stable.

Use the coefficient of variation (CV) to gauge reliability. It tells you how much the attempts scatter. A small CV means the day's measurement was consistent, so you can trust it; an unusually large one is a sign that form was shaky or condition was unstable, so it's worth measuring again.

Use the grade to gauge where they stand. PoinT GO automatically assigns a 5-level grade against sex-specific standards. It's handy for placing an athlete you're measuring for the first time. That said, what ultimately matters more than an absolute grade is that athlete's own change over time.

Read the trend. The real power of jump measurement lies not in a single number but in the flow over time. If the same athlete's jump height climbs for several weeks, training is working; if it stalls or drops for more than two weeks, it may be a sign of insufficient recovery. When that happens, it's good for the coach to look at sleep and training load together.

Compare left and right. Measuring left and right separately with the single-leg CMJ lets you see balance. If one side is noticeably lower, it may signal injury risk or incomplete recovery, which helps with return-to-play decisions and preventive management.

Getting data you can trust

When the measurements wobble, so does the interpretation. Just handling these in the field makes the data far more stable.

  • Measure after warming up. Doing a maximal jump before the body is loose produces low records and raises injury risk. Measure after a light warm-up.

  • Measure under the same conditions. Keeping the time of day, the amount of warm-up, and the countermovement depth similar each time is what makes comparison meaningful. Especially with the CMJ, values wobble when the countermovement depth changes each time.

  • 3-5 attempts is about right. One or two may miss the best record, and too many build up fatigue. Rest well between attempts as you measure.

  • Don't be fooled by the landing. Since jump height is calculated from flight time, tucking the knees up excessively in the air makes it read higher than it really is. Tell the athlete to keep takeoff and landing posture similar.

  • Measure under conditions that fit your purpose. If the goal is ability assessment, measure well-rested; if the goal is fatigue monitoring, measure on the same weekday and time each week.

Managing at the team level

Measuring one person and managing a whole team are different jobs. This is where coach-web (the web dashboard) shows its strength.

  • Per-athlete trends: Lay out an individual athlete's jump records in chronological order and track how much they've risen or fallen against the baseline.

  • Team ranking and best records: Gather best records by event, jump included, at a glance. Good for comparing athletes and setting goals.

  • Program assignment: Build measurement and training programs that include jumps, assign them to athletes, and run them as a regular measurement routine.

The flow is: measure with the app in the field, and that data gets organized at the team level in coach-web. Because the app and the web share the same algorithm, the same jump gives the same result no matter where you measure it.

App or web -- which to measure with

Both handle measurement and analysis fully. The difference isn't capability, it's the situation.

  • In the field or on the move, the connect app: With just a phone you can measure right away, and it's great for cycling through multiple athletes. It's the tool commonly used in gyms and on the field.

  • To manage a team systematically, coach-web: This is where you organize teams, permissions, and programs on a desktop and compare and analyze the accumulated data. You can also connect a sensor and measure live on the web (desktop Chrome and Edge).

Usually the natural combination is measuring in the field with the app and reviewing it all together on the web.

Frequently asked questions

Q. Jump measurement -- should I use the app or the web?

Both do measurement. If you'll be cycling through athletes in the gym or on the field, the connect app on your phone is convenient; if your goal is to organize and compare team data, manage it in coach-web. On the web too, you can connect a sensor with desktop Chrome or Edge and measure right away.

Q. My jump height comes out a little different each time -- is that okay?

That's normal. Even under the same conditions on the same day, a person jumps a little differently each time. So rather than getting caught up in 1-2 cm differences, it's better to compare using the best height or the average of the top 3. PoinT GO also shows you, via the coefficient of variation (CV), how consistent the day's measurement was, so if the CV is unusually large, measure again.

Q. How many times should I jump, and which value should I record?

3-5 times is about right. Measure with plenty of rest between attempts, and record the best height or the top-3 average as your representative value. A good rhythm is ability assessment once every 4-6 weeks, and an easy in-season condition check every week under the same conditions.

Q. Can I also see left-right balance from jumps?

Yes. Measuring left and right separately with the single-leg CMJ lets you compare balance. If one side is noticeably lower, it may signal injury risk or incomplete recovery, so it's worth referring to for return-to-play decisions and preventive management. Measuring with both legs only can let the strong side mask the weak one, so if balance is a concern, measure single-leg.

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