Start here
Try your own comparison in under a minute
Leave the default pair in place for a moment. Switch from Standing to Seated and watch the gap change. Once the idea is clear, replace the two heights with people you actually want to compare.
Type the standing heights
Open Person A, then Person B. The sitting height estimate updates as soon as each standing height changes.
Switch to Seated
Compare the head line on the shared bench, then switch back to Standing whenever you want to check the original gap.
Use Measured only when it is real
If you took a seat-to-head measurement, turn on Measured for that person and enter it. Otherwise, leave the estimate in place.
What changes
Same two people. Same seat. A very different gap.
Sitting height is simply the distance from the seat to the top of the head. Put two people on the same bench and most of their leg length drops out of the visible height difference.
That is the whole point of this comparison. A clear standing lead can shrink to a few centimeters. Sometimes it disappears. Sometimes the shorter person even sits taller.
- Standing gap
- The difference between the tops of two heads while standing.
- Seated gap
- The head-to-head difference after both people share one seat line.
- Height flip
- The shorter standing person becomes the taller seated person.
- Sitting height
- The seat-to-head number used to create the seated comparison.
The common surprise
Long legs can make a big lead disappear
Someone can look much taller while standing, then only slightly taller when seated. Usually, a larger share of that standing lead came from the legs.
The shorter person may have more height above the seat, so their head ends up closer than expected. This is why couples, friends, siblings, and fictional characters can look like a different height pairing as soon as they sit beside each other.
The shared bench keeps the result easy to read. No taller chair, no deeper cushion, no camera trick. Just look at the two head lines and see how much of the original gap remains.
The default pair
Ten centimeters standing. Less than half that on the bench.
Person A starts at 180 cm. Person B starts at 170 cm. The standing gap is an easy 10 cm, large enough to notice immediately. Their estimated sitting height values are 94.0 cm and 89.4 cm, so the same pair ends up only about 4.6 cm apart on the bench.
Try this before entering your own numbers. The change is easier to understand when you see it happen. Then edit either standing height and watch the seated gap respond. If one person has a real sitting height measurement, replace only that person's estimate; the other result can stay automatic.
- Standing gap
- 10 cm
- Estimated seated gap
- 4.6 cm
Full stature, including the legs.
Seat surface to head, using reference estimates.
Keep it simple
Start with the estimate. Measure only if you want to.
You do not need a tape measure to try the comparison. Enter each person's standing height and HowHeight fills in an estimated sitting height automatically.
For a quick look at a partner, friend, sibling, celebrity, or character pairing, the estimate is enough. Switch between Standing and Seated and watch the visible gap shrink, stay close, or reverse.
Of course, two people at the same standing height do not always have the same sitting height. The estimate cannot know every person's exact proportions. It is there to get the comparison moving, not to make you fill out a long form.
If you already know the real seat-to-head number, turn on Measured for that person and enter it. The scene updates straight away. Everyone else can keep using the automatic estimate.
The number that matters
How much of the standing gap is left?
The default pair starts 10 cm apart. On the bench, that becomes about 4.6 cm. More than half of the visible difference is gone.
10 cm standing / 4.6 cm seated
That before-and-after gap is usually easier to understand than a sitting height ratio. If you do want the ratio, divide sitting height by standing height. For an ordinary comparison, the two gap numbers tell the story faster.
Have a real measurement?
Use it, but do not make it homework
The automatic estimate is fine for exploring. If you want your own number, use a firm seat beside a wall and skip the sofa. A soft cushion can change the result before you even start.
- Sit upright with the hips against the wall and keep the head level.
- Support both thighs and keep the pelvis level on the seat.
- Measure straight up from the seat surface to the highest point of the head.
- Do it once more. If the numbers disagree, reset the posture and try again.
Make it personal
Try a pair you actually care about
Use your own name and your partner's. Compare two friends, two siblings, a cast, or characters from a story. The result becomes much more interesting when Person A and Person B stop feeling like placeholders.
Start in Standing, then tap Seated. Move between the two views to compare how much the gap changes. Front view makes the head gap obvious; Side view gives the comparison more personality and shows how each person sits on the bench.
Sitting height questions
What is sitting height?
Sitting height is the distance from a firm seat to the top of the head while you sit upright. The chair is not part of the number, and neither is most of your leg length. That is why sitting height is not the same as torso length or floor-to-head height on a chair.
How does the sitting height estimate work?
Enter a standing height and choose the adult reference model. HowHeight uses paired NHANES III standing and sitting measurements to produce a central estimate. It is a sensible starting point, not a secret measurement of your body. Only turn on Measured when you have taken a real seat-to-head measurement.
What is the sitting height ratio?
Divide sitting height by standing height and multiply by 100. A sitting height of 90 cm with a standing height of 175 cm gives about 51.4%. The ratio describes proportion. It is not a health score and does not label a body as normal or abnormal.
Why can two people look closer in height when seated?
Because the legs stop doing most of the work. Put both people on the same seat line and the visible gap is driven much more by the pelvis, spine, neck, and head. A 10 cm standing difference can therefore shrink sharply once both people sit upright.
Can a shorter person look taller while seated?
Yes. A shorter person may carry more of their height above the seat, while the taller person may carry more in the legs. The seated order can reverse even though the standing heights have not changed.
Is the estimated sitting height exact?
No. Standing height cannot reveal your exact leg, spine, neck, and head proportions. Read the estimate as a plausible starting point. For a personal result, measure from a firm seat to the top of the head, then enable Measured for that person.
Does chair height change the comparison?
Chair height changes floor-to-head height, but not the gap between two people sharing the same firm seat. Soft cushions and relaxed posture are different: they can lower one person more than another. The bench here is a controlled baseline, not a recreation of every chair.
Can this tool assess a child's growth or a medical condition?
No. The estimator is built around adult reference data for ages 18 and older. Children need age-specific growth references, and medical questions need a qualified clinician. This page is a visual comparison tool, not a diagnostic test.