Hong Life CalculatorsAll converters
Length & area
- Length Converter (m, ft, in, yd)
- Nautical Mile Converter (NM, km, mi)
- Astronomical Distance Converter (AU, light-year, parsec)
- Micrometer, Nanometer & Ångström Converter
- Traditional Length Converter (치·자·간·리 / 寸·尺·間·里)
- Area Converter (m², ft², yd²)
- Land Area Converter (acre, hectare, pyeong)
- Feet and Inches Calculator (add, subtract, multiply, to cm)
- Height in Inches Calculator (cm ↔ feet and inches)
- Inches to Fraction Calculator (decimal inches or mm → 1/16, 1/32, 1/64)
Volume
- Volume Converter (L, mL, m³, ft³)
- Gallon Converter (US & UK gallons, quarts, pints)
- Cooking Measurement Converter (cups, tbsp, tsp, mL)
- Oil Barrel Converter (bbl to liters & m³)
- Board Foot Converter (board feet, 재/才, m³)
- Cubic Yards to Tons Calculator (yd³ × density → US tons, tonnes)
Mass & weight
- Weight Converter (kg, lb, oz, g)
- Ton Converter (metric, short & long tons)
- Gold Weight Converter (troy ounce, 돈, 냥, carat, gram)
- Traditional Weight Converter (근·냥·돈·관)
- Grain Conversion Calculator (bushels ↔ tonnes, kg, lb for wheat, corn, soybeans…)
- Pounds and Ounces Calculator (add, subtract, multiply, to kg)
Pressure, force & density
- Density Converter (g/cm³, kg/m³, lb/ft³)
- Pressure Converter (Pa, kPa, MPa, bar)
- PSI Converter (psi, atm, kgf/cm², torr)
- Water Column Converter (mmH₂O, inH₂O)
- Vacuum Converter (mbar, microns, torr)
- Force Converter (N, kgf, lbf, dyn)
- Torque Converter (N·m, kgf·m, lb·ft, lb·in)
- Spring Rate Converter (N/mm, kgf/mm, lbf/in)
Energy & power
- Energy Converter (J, kJ, cal, kcal)
- BTU Converter (BTU, therm, ft·lbf)
- kWh Converter (Wh, kWh, MWh, joules)
- Electronvolt Converter (eV, keV, MeV, J)
- Power Converter (W, kW, MW)
- Horsepower Converter (PS, HP, kW)
- Refrigeration Ton Converter (US RT vs Japanese/Korean RT)
- CCF to Therms Calculator (gas bill CCF, MCF → therms, kWh, cost)
- Natural Gas Converter (m³, ft³, CCF, MCF ↔ MJ, kWh, therms, MMBtu)
Speed & motion
- Speed Converter (m/s, km/h, mph, knots)
- Mach Number Converter (Mach to km/h, mph, ft/s)
- Acceleration Converter (m/s², g, Gal)
- Angular Velocity Converter (rad/s, °/s, RPM)
- Kinematic Viscosity Converter (St, cSt, m²/s)
- Dynamic Viscosity Converter (Pa·s, poise, cP)
- Surface Tension Converter (N/m, mN/m, dyn/cm)
Flow
- Flow Rate Converter (m³/h, L/min, L/s, CFM)
- GPM Converter (gallons per minute, barrels per day, m³/day)
- Mass Flow Converter (kg/s, kg/h, t/h, lb/h)
Heat & insulation
- Thermal Conductivity Converter (W/m·K, kcal/m·h·°C, BTU/h·ft·°F)
- U-Value ⇄ R-Value Converter (SI and US)
- Specific Heat Converter (J/kg·K, cal/g·°C, BTU/lb·°F)
Electricity & magnetism
- Charge Converter (mAh, Ah, coulombs)
- Voltage Converter (V, mV, kV, µV)
- Current Converter (A, mA, µA, biot)
- Resistance Converter (Ω, kΩ, MΩ, µΩ)
- Capacitance Converter (F, µF, nF, pF)
- Inductance Converter (H, mH, µH)
- Conductivity Converter (S/m, mS/cm, µS/cm, mho)
- Magnetic Flux Density Converter (tesla, gauss)
- Magnetic Flux Converter (weber, maxwell)
- Magnetomotive Force Converter (ampere-turn, gilbert)
- RF Unit Converter (dBm, dBW, W, dBµV, dBmV, V at 50/75 Ω)
Radiation & light
- Radioactivity Converter (becquerel, curie)
- Absorbed Dose Converter (gray, rad)
- Radiation Dose Converter (sievert, rem, mSv)
- Radiation Exposure Converter (roentgen, C/kg)
- Luminous Intensity Converter (candela, candlepower)
- Lumens ⇄ Candela Converter (beam angle)
- Illuminance Converter (lux, foot-candles)
- Luminance Converter (nits, cd/m², foot-lamberts)
- Diopter ⇄ Focal Length Converter
Angle & time
- Angle Converter (degrees, DMS, radians, gradians)
- Mil Converter (NATO 6400, Warsaw Pact 6000, degrees)
- Field of View Calculator (focal length & sensor)
- Time Unit Converter (years to nanoseconds)
- Time Zone Converter (world cities, daylight saving aware)
- Leap Year Calculator (is it a leap year? 365 or 366 days)
- Day of the Week Calculator (Zeller’s congruence)
- Military Time Converter (12-hour ↔ 24-hour clock)
Concentration & lab
- Concentration Converter (mol/L, g/L, ppm, ppb)
- Gas Concentration Converter (ppm ⇄ mg/m³)
- Blood Sugar Converter (mg/dL ⇄ mmol/L)
- Cholesterol & Triglyceride Converter (mg/dL ⇄ mmol/L)
- mg to mL Calculator (mass ↔ volume at a known concentration)
Sizes & standards
- Shoe Size Converter (KR mm, JP cm, US, UK, EU)
- Men’s Clothing Size Converter (KR 95/100/105, S–XXL, EU)
- Women’s Clothing Size Converter (KR 55/66/77, US, UK, IT, FR)
- Waist Size Converter (inches ⇄ cm)
- Bra Size Calculator (underbust & bust, KS/JIS cup)
- Ring Size Converter (Korea/Japan 호, US, EU, inner diameter)
- Hat Size Converter (head cm ⇄ US/UK fitted)
- Glove Size Calculator (hand circumference)
- Mattress Size Chart (Korea, US, UK, EU)
- Duvet & Sheet Size Chart (matching your mattress)
- A Paper Sizes (A0–A10) in mm and inches
- B Paper Sizes (ISO B and JIS/KS B)
- US Paper Sizes (Letter, Legal, Tabloid) vs A4
- Book Trim Sizes (국판·신국판·46판·크라운판)
- DPI Print Size Calculator (pixels ⇄ cm)
- Screen Aspect Ratio Calculator (16:9, 21:9, 4:3 …)
- TV Size Calculator (inches → width, height, area)
- Pixel Density Calculator (PPI)
- Screen Resolution Chart (HD, FHD, QHD, 4K, 8K)
- TV Viewing Distance Calculator (30° and 40° rules)
- Camera Sensor Size Calculator (1/1.3″, 1″ …)
- Crop Factor Calculator (full-frame equivalent)
- Exposure Value (EV) Calculator
- Depth of Field & Hyperfocal Calculator
- Flash Guide Number Calculator (f = GN ÷ distance)
- Piano Keyboard Width Calculator (88, 76, 61 keys)
- Violin & Cello Size Chart (by arm length / height)
- Golf Shaft Flex Chart (swing speed)
- Ski & Snowboard Length Calculator
- Badminton Racket U & Tennis Grip Size Chart
- Bowling Ball Weight Calculator (10% rule)
- Fishing Line 호 (Gou) to Diameter Chart
- Fishing Sinker 호 ⇄ Grams Converter
- Leather Area Calculator (DS ⇄ sq ft)
- Denier ⇄ Tex ⇄ Dtex Converter
- Cotton Count (Ne) ⇄ Denier & Tex Converter
- Sewing Machine Needle Size Chart (NM ⇄ US/JP)
- Knitting Needle Size Chart (mm, US, Korea/Japan 호)
- AWG Wire Gauge Calculator (diameter, mm², resistance)
- Sheet Metal Gauge Chart (steel & aluminum)
- Rebar Size Chart (Korean D10–D32, weight per meter)
- Pipe Size Chart (A ⇄ B, OD, Sch 40/80)
- Lumber Size Chart (nominal 2×4 vs actual)
- Screw Thread Chart (metric M ⇄ UNC/UNF)
- Drill Bit Size Converter (fractional inch ⇄ mm)
- Sandpaper Grit Chart (FEPA P grit → particle size)
- Battery Size Chart (AA, AAA, C, D, 9V, 18650, 21700)
- Coin Cell Battery Code Decoder (CR2032 …)
- USB Speed & Power Chart (USB 2.0 to USB4, PD)
- HDMI & DisplayPort Bandwidth Calculator
- Alcohol Content Calculator (mL × ABV → grams)
- Wine & Champagne Bottle Size Chart
- Shot Size Converter (oz ⇄ mL)
- Knife & Pan Size Converter (inches ⇄ cm)
- Aquarium Volume & Weight Calculator
- Flower Pot Size Calculator (호 ⇄ cm, soil volume)
- Carry-on Luggage Size Checker (115 cm rule)
- Cabin Liquids Checker (100 mL / 1 L bag)
- Passport & ID Photo Pixel Calculator
- Bicycle Tire Size Chart (ETRTO ⇄ inch ⇄ French)
- Wheelchair Ramp Length Calculator (1:12)
- Elevator Capacity Calculator (persons ⇄ kg)
- Pallets per Container Calculator (20ft / 40ft)
- Shipping Container Volume (CBM) Chart
- Air Freight Volumetric Weight Calculator (L × W × H ÷ 6000)
- Mesh to Micron Converter (ASTM E11 sieve No. ↔ µm)
Maps & coordinates
Numbers & number names
- Billion to Trillion Converter (thousand, million, billion, trillion)
- Million to Billion Converter (with Korean 만·억·조)
- Crore to Lakh Converter (Indian number system)
- Crore to Million Converter (crore, lakh ↔ million, billion)
- Million to Lakh Converter (million ↔ lakh, crore)
- Paper Quantity Converter (sheets, quires, reams, boxes)
- Quantity Converter (pieces, pairs, dozens, scores, gross)
All-in-one
- CGS System of Units Converter (dyne, erg, gauss, poise, stokes ↔ SI)
- All-in-One Unit Converter (length, weight, volume, temperature & more)
Fuel economy
- Price per Liter to Price per Gallon Converter (US & imperial gallons)
- MPG to L/100 km Converter (US & UK mpg, km/L)
Money & coins
FAQ
Are these conversions exact?
Factors come from SI definitions and NIST SP 811. Results are rounded to 10 significant digits.
Checked 8 Nov 2026. BIPM SI Brochure (9th ed.), NIST SP 811 Appendix B.