🔢 Converters & References

Dental Unit Converter

Real-time conversion for dental clinical measurements. Millimetres to inches, kilograms to pounds, Celsius to Fahrenheit, and pressure units. Type in either field to convert instantly.

Real-Time mm ↔ inches kg ↔ lbs °C ↔ °F PSI ↔ kPa
Dental Unit Converter
Type in either field — converts in real time
📏 Length / Probe Depth / Restoration Dimensions
Millimetres (mm)
Common: probe depth 1-9 mm, screw diameter 3.3-5 mm
⇄
Inches (in)
1 mm = 0.03937 in
Centimetres (cm)
Common: crown height 0.5-1.5 cm
⇄
Inches (in)
1 cm = 0.3937 in
⚖️ Weight (Patient / Anaesthetic Dosing)
Kilograms (kg)
Standard for anaesthetic dosing calculations
⇄
Pounds (lbs)
1 kg = 2.20462 lbs
Kilograms (kg)
Convert to stones and pounds
⇄
Stones (st)
1 stone = 6.35029 kg
🌡️ Temperature (Autoclave / Material Setting)
Celsius (°C)
Autoclave standard: 121°C (gravity) or 134°C (pre-vac)
⇄
Fahrenheit (°F)
Autoclave standard: 250°F (gravity) or 270°F (pre-vac)
💨 Pressure (Autoclave / Dental Air)
PSI (pounds per sq inch)
Autoclave standard: 15 PSI (gravity) or 30 PSI (pre-vac)
⇄
kPa (kilopascals)
1 PSI = 6.89476 kPa
Bar
Dental compressor: 5-8 bar typical
⇄
PSI
1 bar = 14.5038 PSI
🧪 Volume (Medication / Material)
Millilitres (mL)
Standard dental cartridge = 1.8 mL
⇄
Fluid ounces (fl oz)
1 mL = 0.033814 fl oz
Common Dental Reference Conversions
MeasurementMetricImperialClinical Use
Probe depth (deep)6 mm0.24 inPeriodontal pocket - high risk
Implant diameter (narrow)3.3 mm0.13 inNarrow ridge placement
Implant diameter (standard)4.1 mm0.16 inMost common adult implant
Autoclave temp (gravity)121°C250°FStandard wrapped instruments
Autoclave temp (pre-vac)134°C270°FPre-vacuum cycle
LA cartridge volume1.8 mL0.06 fl ozStandard dental cartridge
Adult average weight70 kg154 lbsBaseline for dosing calculations
Dental air supply550-690 kPa80-100 PSIDental handpiece supply pressure

Metric and imperial in dentistry

Dentistry sits at the intersection of metric and imperial measurement systems - particularly in North America where clinical measurements are metric but patients report their weight in pounds and autoclave manuals sometimes use Fahrenheit. This converter handles the most common conversions that come up daily in a dental setting.

The most clinically critical conversions are for anaesthetic dosing: the maximum recommended dose calculations in our Anaesthesia Dosage Calculator use kilograms. If a patient tells you their weight in pounds, convert here first. An error in weight-based dosing can have significant clinical consequences.

For pressure and temperature in the context of autoclave compliance, use these conversions alongside our Sterilization Cycle Log which records all cycle parameters.

Frequently Asked Questions

Periodontal probes are calibrated in millimetres because the clinically significant thresholds (3mm, 4mm, 6mm) are standardised internationally using the metric system. The WHO and all major periodontal societies publish research and guidelines in metric. Even in the United States, periodontal probing is always done and documented in millimetres. This is one area where the profession adopted metric universally regardless of local measurement conventions.
Dental compressors typically deliver 80-100 PSI (550-690 kPa) at the handpiece. High-speed handpieces require adequate pressure to maintain cutting efficiency. Most manufacturers specify 32 PSI (220 kPa) at the handpiece coupling as the minimum for proper turbine operation. Chair-mounted air/water syringes typically operate well at 40-60 PSI (275-415 kPa). Always check your specific handpiece manufacturer's recommended operating pressure.

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