Free Desk Height Calculator
Enter your height and this desk height calculator returns your ergonomic desk surface height, monitor position, and chair seat height — based on OSHA and ANSI/HFES ergonomic ratios, updated live, as you type.
On this page10 sections
Ergonomic estimates based on standard proportional ratios. Individual body proportions vary — adjust to comfort.
Results are estimates. Consult a professional.
How the desk height calculator works
The calculator uses a set of proportional ratios derived from large-scale ergonomics studies and codified in OSHA computer workstation guidelines and ANSI/HFES 100-2007. Your standing height predicts your seated elbow height — which is the ergonomic target for desk surface height — as well as your seated eye level for the monitor and the chair seat height needed to keep your knees at 90°.
Why desk height determines your sitting posture
A desk that is even an inch too high forces your shoulders to shrug slightly while you type. Over an eight-hour day, that constant low-level tension is a direct cause of neck pain, shoulder pain, and repetitive strain injuries. A desk that is too low pushes you into a hunched forward lean, loading the lower back. The ergonomic goal is neutral: upper arms hanging vertically, forearms horizontal, wrists straight, and eyes looking slightly downward — a position you can hold for hours without accumulating strain.
The seated elbow rule
Desk height should equal your seated elbow height — the height of your elbow from the floor when you sit upright with your upper arms hanging naturally at your sides. Most ergonomics guidelines (OSHA, Cornell, BIFMA) agree on this target because it keeps wrists straight and shoulders relaxed during keyboard use.
Wrist angle and keyboard position
Wrist position is where a slightly-wrong desk height shows up as pain first. OSHA recommends keeping wrists flat or in a slight negative (downward) tilt — never bent upward (dorsiflexion) toward the keyboard. An upward wrist bend for hours at a time compresses the carpal tunnel and loads the flexor tendons, which leads to discomfort and over time can contribute to repetitive strain injuries.
Keyboard tray as an alternative
If your desk height is fixed and too high, a keyboard tray that mounts under the desk can achieve the right elbow angle without changing the desk surface. Keyboard trays are a common fix in shared offices where the desk is built to suit the average user. They can also help taller users who need a slightly lower keyboard position than the desk top.
Mouse at the same height as the keyboard
Position the mouse at the same level as the keyboard so your shoulder doesn't rotate out to reach it. Mouse pads that attach to a keyboard tray or an extended tray surface keep both inputs at the correct elbow height without a separate shelf.
How to position your monitor correctly
Monitor height is just as important as desk height. The top of the screen should sit at or slightly below your seated eye level. Looking up at a monitor strains the neck and dries out the eyes (open eye area increases when looking up). Looking steeply down is better than looking up, but still fatiguing over long sessions.
| Measurement | Target | Why |
|---|---|---|
| Top of screen | At eye level | Prevents neck extension; most common OSHA/ergonomics standard |
| Center of screen | 3–5 in below eye level | Natural 10–15° downward gaze; reduces dry-eye and neck strain |
| Distance from eyes | 20–28 in (arm's length) | Reduces eye strain; aligns with the 20-20-20 rule |
| Screen tilt | 10–20° back from vertical | Matches downward line of sight to reduce reflections |
Figures from OSHA eTool for Computer Workstations and the American Academy of Ophthalmology ergonomics guidelines.
For dual-monitor setups, the primary monitor should sit directly in front of you at the correct height. The secondary monitor goes to the side at a slight angle — not fully to the side, which forces neck rotation, but about 15–20° off center. Both screens should be at the same height.
Chair seat height and when you need a footrest
Chair height follows directly from desk height. The goal is 90° knee angles with feet flat on the floor — meaning the chair seat sits about 10.5 inches below the desk surface for most people. If that puts the seat so high your feet can't reach the floor, you need either a lower desk, a height-adjustable chair, or a footrest.
Who needs a footrest
Footrests are typically needed for users shorter than about 5′2″ working at a standard fixed-height desk (usually 28–30 inches), and occasionally for users 5′2″–5′4″ depending on leg proportions. The footrest raises the effective floor height so your feet are supported, your thighs are parallel to the floor, and you're not sitting with your legs dangling or pressed against the seat edge — both of which cut circulation.
Worked example: 5′7″ user (67 inches)
Priya is setting up her desk. She's 5 feet 7 inches tall — 67 inches standing. She wants to know the right desk height, where to put her monitor, and what chair setting to use.
Step 1 — Desk height
67 × 0.254 = 17.0 inches. Her desk surface should be 17 inches from the floor.
Step 2 — Monitor height
Seated eye level = 67 × 0.522 = 35.0 inches. The top of her monitor should be at 35 inches. The center of the screen should sit around 32 inches (3 in below eye level).
Step 3 — Chair height
Chair seat = 17.0 − 10.5 = 6.5 inches. This is a derived ergonomic value — in practice, many standard adjustable chairs have a minimum seat height of 16–18 in. If a standard chair sits too high, she should look for a shorter-cylinder chair or add a footrest to raise the floor to meet her feet.
Standing desks: calculating both sitting and standing heights
Height-adjustable (sit-stand) desks solve the fixed-desk problem for people who don't fit standard furniture. The sitting height from this calculator is your lower limit. The standing desk height follows a different ratio: standing elbow height is roughly your total standing height multiplied by 0.63, which is the height of your elbows when standing with arms at your sides.
For a 5′7″ (67 in) person: standing desk height ≈ 67 × 0.63 = 42.2 inches. The desk should go from about 17 in (sitting) to about 42 in (standing). Most sit-stand desks adjust from roughly 24 to 48 inches, which covers the full adult range.
OSHA recommends alternating sitting and standing throughout the day — not standing all day. A common pattern is 45 minutes seated, 15 minutes standing, adjusted to comfort. The key is that both the sitting and standing heights are set correctly so every position is ergonomic.