# Reading a Ruler & Metric Measurements
A **ruler** is really just a short, stiff tape measure — and it reads the same way.
## The inch side
Same marks as your tape: whole inches, then ½, ¼, ⅛, and 1/16 between them. Read the whole inches first, then the fraction.
## The metric side
Much of the world builds in **metric**, so it pays to know it:
- **Millimeter (mm)** — the smallest common mark.
- **Centimeter (cm)** — = **10 mm**. The numbered marks on a metric ruler are usually centimeters.
- **Meter (m)** — = **100 cm** = **1,000 mm**.
To read metric: count the **centimeters** (numbered), then count the small **millimeter** marks past it. Example: 4 cm and 3 mm = **43 mm** (or 4.3 cm).
## Quick conversions
- **1 inch ≈ 25.4 mm**
- **1 foot ≈ 305 mm (0.305 m)**
- **1 meter ≈ 3.28 feet**
## Why it matters
If you ever work **internationally** — or with metric products and specs — reading both systems makes you far more useful on the job.
**Takeaway:** A ruler reads like a short tape; metric counts in mm, cm, and m. Much of the world is metric — know both if you'll build internationally.
> *Educational overview — practice the hands-on skills with real tools. Repetition is how they become second nature.*
