Everyday calculator
Screen Size Calculator, Dimensions, Aspect Ratio & PPI
Calculate screen width, height, and pixel density (PPI) from diagonal size and resolution. Compare aspect ratios and find ideal viewing distances.
How CalcMesh computes screen dimensions
A screen’s width and height come from its diagonal and aspect ratio by the Pythagorean theorem; a 27-inch 16:9 display, for instance, is about 23.5 inches wide and 13.2 inches tall.
We also derive pixel density (PPI) from the resolution you enter; the geometry we use is documented in our methodology.
Screen Size Guide
Common Screen Sizes
| Device | Size | Resolution |
|---|---|---|
| Smartphone | 6.1-6.7" | 1080x2400 |
| Tablet | 10-13" | 2560x1600 |
| Laptop | 13-16" | 1920x1200 |
| Monitor | 24-32" | 2560x1440 |
| TV | 55-75" | 3840x2160 |
Understanding PPI
Pixels Per Inch (PPI) determines how sharp a display looks. The ideal PPI depends on viewing distance:
- Phones (8-12"): 300+ PPI for crisp text
- Tablets (18-24"): 200-270 PPI
- Monitors (24-36"): 90-160 PPI
- TVs (6-12 ft): 40-80 PPI is fine
Viewing Distance
A common recommendation is to sit at a distance of 1.5 to 2.5 times the screen diagonal. For a 27-inch monitor, that means roughly 40 to 68 inches (3.3 to 5.6 feet) away. Sitting too close to a large screen can cause eye strain, while sitting too far reduces the immersive benefit.
Note: Screen measurements refer to the viewable display area, not including bezels or casing.
Worked example, 27″ 16:9 at 2560×1440
Pythagorean panel math (viewable diagonal, not bezel):
- Aspect 16:9 → width:height = 16:9. Diagonal factor √(16²+9²) = √337 ≈ 18.358.
- Width inches = 27 × 16 / 18.358 ≈ 23.5″; height = 27 × 9 / 18.358 ≈ 13.2″.
- PPI = √(2560²+1440²) / 27 ≈ 108.8 PPI.
- Same 27″ at 1920×1080 drops to ≈ 81.6 PPI - geometry unchanged, sharpness does.
After you size the panel
What to do with the numbers
- Compare monitors on PPI + viewing distance, not diagonal alone.
- Ultrawide 21:9 changes width/height for the same diagonal - rerun with the real ratio.
- TV seating at 1.5-2.5× diagonal is a rule of thumb; text work wants higher PPI than couch viewing.
- Manufacturer “27-inch” is the glass diagonal; stands and bezels add desk depth separately.
Methodology & Assumptions
This calendar tool counts civil days and applies stated unit rates to the dates and distances you enter. Time-zone edges follow the browser zone database for your inputs.
How this calendar node runs
Date and rate tools count civil days and apply stated unit rates. Zone edges follow the browser zone database. Published domain formulas
govern the identities; when an agency updates rates or thresholds we refresh defaults
and the page lastmod.
| Input | Default | Source / authority |
|---|---|---|
| All inputs | Domain-typical defaults | Editorial methodology, CalcMesh 2026 |