Millimeter to Centimeter Converter
Enter the value that you want to convert millimeter (mm) to centimeter (cm) or centimeter to millimeter.Also written as MM to CM conversion.
1 millimeter = 0.1000000 centimeter
Formula: centimeter = millimeter value × 0.1000000
MM to CM — millimeter to centimeter
10 millimeter = 1.00000 centimeter
Popular Length Converters:
How Millimeter Relates to Centimeter
The Millimeter Explained
Millimeter (mm) is a unit of length measurement. 1 millimeter is equal to 0.1000000 centimeter.
What is Centimeter?
Centimeter (cm) is a unit of length measurement. 1 centimeter is equal to 10.0000000 millimeter.
Length Conversions in Practice
Length conversions connect the metric system used by most of the world with the imperial system still dominant in the United States, UK construction, and aviation. Architects convert between meters and feet for international projects. Machinists work in thousandths of an inch while referencing metric specifications. Runners compare kilometer race distances to miles. Screen sizes, paper formats, and fabric measurements all require frequent conversion between systems.
millimeter to centimeter metric conversion table
| 0.01 mm | = | 0.00100 cm |
| 0.1 mm | = | 0.01000 cm |
| 1 mm | = | 0.10000 cm |
| 2 mm | = | 0.20000 cm |
| 3 mm | = | 0.30000 cm |
| 4 mm | = | 0.40000 cm |
| 5 mm | = | 0.50000 cm |
| 6 mm | = | 0.60000 cm |
| 7 mm | = | 0.70000 cm |
| 8 mm | = | 0.80000 cm |
| 9 mm | = | 0.90000 cm |
| 10 mm | = | 1.00000 cm |
| 11 mm | = | 1.10000 cm |
| 12 mm | = | 1.20000 cm |
| 13 mm | = | 1.30000 cm |
| 14 mm | = | 1.40000 cm |
| 15 mm | = | 1.50000 cm |
| 16 mm | = | 1.60000 cm |
| 17 mm | = | 1.70000 cm |
| 18 mm | = | 1.80000 cm |
| 19 mm | = | 1.90000 cm |
| 20 mm | = | 2.00000 cm |
| 30 mm | = | 3.00000 cm |
| 40 mm | = | 4.00000 cm |
| 50 mm | = | 5.00000 cm |
| 60 mm | = | 6.00000 cm |
| 70 mm | = | 7.00000 cm |
| 80 mm | = | 8.00000 cm |
| 90 mm | = | 9.00000 cm |
| 100 mm | = | 10.00000 cm |
| 200 mm | = | 20.00000 cm |
| 300 mm | = | 30.00000 cm |
| 400 mm | = | 40.00000 cm |
| 500 mm | = | 50.00000 cm |
| 600 mm | = | 60.00000 cm |
| 700 mm | = | 70.00000 cm |
| 800 mm | = | 80.00000 cm |
| 900 mm | = | 90.00000 cm |
| 1000 mm | = | 100.00000 cm |
How to Convert MM to CM (Millimeter to Centimeter)?
We can convert millimeter to centimeter by using an example.
Example:
Convert 20 Millimeter to Centimeter?
We know 1 Millimeter = 0.1000000 centimeter; 1 Centimeter = 10.0000000 millimeter.
20 millimeter = ___cm
20 × 0.1000000 = 2.00000 cm (we know 1 millimeter = 0.1000000 centimeter)
Answer:
20 millimeter = 2.00000 centimeter
How to Convert Millimeters to Centimeters (Step-by-Step)
Converting millimeters to centimeters is a simple metric-to-metric conversion used constantly in jewelry sizing, watchmaking, and dental measurements. Since 1 cm = 10 mm, divide by 10.
- Write down the measurement in millimeters (mm).
- Divide the mm value by 10.
- The result is the equivalent length in centimeters (cm).
Common Millimeter to Centimeter Conversions
Everyday mm-to-cm conversions for jewelry, watchmaking, dental, and small-item measurements.
| Millimeter | Centimeter |
|---|---|
| 1 mm | 0.1 cm |
| 5 mm | 0.5 cm |
| 10 mm | 1.0 cm |
| 18 mm | 1.8 cm |
| 25 mm | 2.5 cm |
| 40 mm | 4.0 cm |
| 52 mm | 5.2 cm |
| 100 mm | 10.0 cm |
Solved Examples: mm to cm
Question 1: A diamond is 6.5 mm in diameter. What is this in centimeters?
Solution:
cm = mm ÷ 10
= 6.5 ÷ 10
= 0.65 cm
Answer: 6.5 mm = 0.65 cm (approximately 1 carat round diamond diameter)
Question 2: A watch case measures 42 mm. Express in centimeters.
Solution:
cm = 42 ÷ 10
= 4.2 cm
Answer: 42 mm = 4.2 cm (a large men's sport watch)
Question 3: A dental crown prep margin is 1.5 mm. Convert to cm.
Solution:
cm = 1.5 ÷ 10
= 0.15 cm
Answer: 1.5 mm = 0.15 cm (standard dental preparation depth)
Question 4: A phone is 7.8 mm thick. How many centimeters is that?
Solution:
cm = 7.8 ÷ 10
= 0.78 cm
Answer: 7.8 mm = 0.78 cm (less than 1 centimeter thick)
Practice Questions
Try solving these on your own to test your understanding:
- Convert 35 mm (camera film) to cm. (Answer: 3.5 cm)
- A ring band is 4 mm wide. What is this in cm? (Answer: 0.4 cm)
- Convert 250 mm to cm. (Answer: 25 cm)
- An earring is 12 mm long. How many cm? (Answer: 1.2 cm)
- Convert 0.5 mm (mechanical pencil lead) to cm. (Answer: 0.05 cm)
Jewelry Sizing: Why mm Matters
The jewelry industry works primarily in millimeters for precision. Ring sizes are based on inner circumference: US size 5 = 49.3 mm, size 6 = 52.4 mm, size 7 = 54.4 mm, size 8 = 57.15 mm, size 9 = 59.5 mm. Diamond sizes are measured in mm diameter: 0.25ct ≈ 4.1 mm, 0.5ct ≈ 5.2 mm, 1ct ≈ 6.5 mm, 2ct ≈ 8.2 mm. Chain thickness: delicate = 1-1.5 mm, standard = 2-3 mm, bold = 4-6 mm. All these convert to cm by dividing by 10.
Watchmaking: Case Sizes in mm and cm
Watch sizes are universally expressed in mm (case diameter). Standard ranges: women's watches 26-36 mm (2.6-3.6 cm), unisex 36-40 mm (3.6-4.0 cm), men's standard 40-44 mm (4.0-4.4 cm), oversized 44-50 mm (4.4-5.0 cm). Lug width (strap attachment) is also in mm: 18 mm, 20 mm, 22 mm are most common. Case thickness matters for comfort: dress watches 6-8 mm (0.6-0.8 cm), sport watches 10-14 mm (1.0-1.4 cm), dive watches 14-17 mm (1.4-1.7 cm).
Medical and Dental Measurements in mm
Healthcare professionals use millimeters for precision measurements. Dental: cavity depth 1-3 mm, crown preparation 1.5-2 mm reduction, periodontal pocket depth (healthy: 1-3 mm, diseased: 4+ mm). Dermatology: mole measurements use the ABCDE rule where diameter > 6 mm (0.6 cm) warrants investigation. Ophthalmology: pupil diameter 2-8 mm, corneal thickness ≈ 0.5 mm. These are reported in mm for precision but may need cm conversion for forms.
Key Takeaways
- Divide mm by 10 to get cm (just move the decimal point left).
- 10 mm = 1 cm exactly (both are metric units).
- Jewelry, watches, and dental work all use mm for precision.
- A 1-carat diamond ≈ 6.5 mm = 0.65 cm diameter.
- Standard men's watch: 40-44 mm = 4.0-4.4 cm case diameter.
- No rounding errors — this is an exact conversion within the metric system.
Millimeter to Centimeter Conversion Formula
centimeter = millimeter × 0.1000000
1 millimeter = 0.1000000 centimeter
1 centimeter = 10.0000000 millimeter
Reverse: millimeter = centimeter × 10.0000000
Frequently Asked Questions
How many centimeter are in 1 millimeter?
There are 0.1000000 centimeter in 1 millimeter. To convert millimeter to centimeter, multiply the value by 0.1000000.
How do I convert millimeter to centimeter?
Multiply your millimeter value by 0.1000000 to get the equivalent in centimeter. For example, 5 millimeter = 5 × 0.1000000 = 0.50000 centimeter.
How do I convert centimeter to millimeter?
Multiply your centimeter value by 10.0000000 to get the equivalent in millimeter. Alternatively, divide by 0.1000000.
What is 10 millimeter in centimeter?
10 millimeter is equal to 1.00000 centimeter.
What is 100 millimeter in centimeter?
100 millimeter is equal to 10.00000 centimeter.