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Joule to Watt-hour

Professional J to Wh conversion.

Joule
The SI unit of work or energy, equal to the work done by a force of one newton.
Watt-hour
Unit of energy equivalent to one watt of power for one hour.
Quick LinksLogic & FormulaFAQ
0.00027778
Unit
  • Electronvolt
    eV
  • Attojoule
    aJ
  • Rydberg energy
    Ry
  • Hartree energy
    Eh
  • Kiloelectron-volt
    keV
  • Megaelectron-volt
    MeV
  • Nanojoule
    nJ
  • Dyne-centimeter
    dyn·cm
  • Erg
    erg
  • Microjoule
    µJ
  • Gram-force centimeter
    gf·cm
  • Millijoule
    mJ
  • Inch-ounce
    in·ozf
  • Ounce-force inch
    ozf·in
  • Gram-force meter
    gf·m
  • Poundal foot
    pdl·ft
  • Kilogram-force centimeter
    kgf·cm
  • Inch-pound
    in·lbf
  • Pound-force inch
    lbf·in
  • Joule
    J
  • Newton-meter
    N·m
  • Watt-second
    W·s
  • Foot-pound
    ft·lbf
  • Pound-force foot
    lbf·ft
  • Calorie
    cal
  • Calorie (th)
    cal (th)
  • Calorie (IT)
    cal (IT)
  • Kilogram-force meter
    kgf·m
  • Kilopond meter
    kp·m
  • Kilojoule
    kJ
  • Kilowatt-second
    kW·s
  • BTU (th)
    Btu (th)
  • BTU (IT)
    Btu (IT)
  • BTU
    BTU
  • Watt-hour
    Wh
  • Food Calorie
    Cal
  • Kilocalorie
    kcal
  • Kilocalorie (th)
    kcal (th)
  • Calorie (nutritional, IT)
    Cal
  • Kilocalorie (IT)
    kcal (IT)
  • Megajoule
    MJ
  • Horsepower (Metric) hour
    PS·h
  • Horsepower hour
    hp·h
  • Kilowatt-hour
    kWh
  • Ton-hour (refrigeration)
    TR·h
  • Therm (US)
    therm (US)
  • Therm
    therm
  • Therm (EC)
    therm (EC)
  • Gigajoule
    GJ
  • Mega BTU (IT)
    MBtu (IT)
  • Megawatt-hour
    MWh
  • Ton (TNT)
    ton TNT
  • Fuel oil equivalent (barrel US)
    FOE/bbl
  • Fuel oil equivalent (kiloliter)
    FOE/kL
  • Gigawatt-hour
    GWh
  • Kiloton (TNT)
    kton
  • Megaton (TNT)
    Mton
  • Gigaton (TNT)
    Gton
Unit
  • Electronvolt
    eV
  • Attojoule
    aJ
  • Rydberg energy
    Ry
  • Hartree energy
    Eh
  • Kiloelectron-volt
    keV
  • Megaelectron-volt
    MeV
  • Nanojoule
    nJ
  • Dyne-centimeter
    dyn·cm
  • Erg
    erg
  • Microjoule
    µJ
  • Gram-force centimeter
    gf·cm
  • Millijoule
    mJ
  • Inch-ounce
    in·ozf
  • Ounce-force inch
    ozf·in
  • Gram-force meter
    gf·m
  • Poundal foot
    pdl·ft
  • Kilogram-force centimeter
    kgf·cm
  • Inch-pound
    in·lbf
  • Pound-force inch
    lbf·in
  • Joule
    J
  • Newton-meter
    N·m
  • Watt-second
    W·s
  • Foot-pound
    ft·lbf
  • Pound-force foot
    lbf·ft
  • Calorie
    cal
  • Calorie (th)
    cal (th)
  • Calorie (IT)
    cal (IT)
  • Kilogram-force meter
    kgf·m
  • Kilopond meter
    kp·m
  • Kilojoule
    kJ
  • Kilowatt-second
    kW·s
  • BTU (th)
    Btu (th)
  • BTU (IT)
    Btu (IT)
  • BTU
    BTU
  • Watt-hour
    Wh
  • Food Calorie
    Cal
  • Kilocalorie
    kcal
  • Kilocalorie (th)
    kcal (th)
  • Calorie (nutritional, IT)
    Cal
  • Kilocalorie (IT)
    kcal (IT)
  • Megajoule
    MJ
  • Horsepower (Metric) hour
    PS·h
  • Horsepower hour
    hp·h
  • Kilowatt-hour
    kWh
  • Ton-hour (refrigeration)
    TR·h
  • Therm (US)
    therm (US)
  • Therm
    therm
  • Therm (EC)
    therm (EC)
  • Gigajoule
    GJ
  • Mega BTU (IT)
    MBtu (IT)
  • Megawatt-hour
    MWh
  • Ton (TNT)
    ton TNT
  • Fuel oil equivalent (barrel US)
    FOE/bbl
  • Fuel oil equivalent (kiloliter)
    FOE/kL
  • Gigawatt-hour
    GWh
  • Kiloton (TNT)
    kton
  • Megaton (TNT)
    Mton
  • Gigaton (TNT)
    Gton
Precision: 8 decimal places

Logic & Formula

To convert Joule to Watt-hour, we use the specific conversion ratio for this category. 1 J is equal to 0.00027778 Wh.

Value in Wh = (Value in J * 1) / 3600

Unit Definitions

Joule

The SI unit of work or energy, equal to the work done by a force of one newton.

Watt-hour

Unit of energy equivalent to one watt of power for one hour.

Verified 2026 Standards
Industrial Precision

How to convert Joule to Watt-hour?

Enter the value in Joule, choose the target unit Watt-hour, and the result updates instantly. This page also includes the conversion formula and a quick reference table for verification.

Formula: Value in Wh = Value in J × 0.00027778

Common Conversions Table

Value (J)Result (Wh)
10.00027778
100.00277778
250.00694444
500.01388889
1000.02777778
10000.27777778

FAQ

What is the conversion formula from J to Wh?
Value in Wh = Value in J × 0.00027778
What is the smallest unit in Energy?
The smallest unit (as defined on this site) is: Electronvolt (eV). For higher precision, convert using a smaller unit first.
Are the results accurate?
Yes. Conversions run locally in your browser using verified ratios and display up to 8 decimals. Some categories like temperature and fuel use specialized formulas.

About this conversion

This page converts Joule to Watt-hour using verified ratios and includes tables, examples, and FAQs for quick verification.

Joule
The SI unit of work or energy, equal to the work done by a force of one newton.
Watt-hour
Unit of energy equivalent to one watt of power for one hour.

Formula and precision

Value in Wh = Value in J × 0.00027778
1 J is equal to 0.00027778 Wh.
Yes. Conversions run locally in your browser using verified ratios and display up to 8 decimals. Some categories like temperature and fuel use specialized formulas.
  • Use smaller units for higher precision, then convert back if needed.
  • Temperature and fuel categories can’t be reduced to one constant multiplier.
  • Symbols vary by region (US/UK gallons, metric vs. imperial abbreviations).
  • For engineering work, validate with a second reference and keep unit symbols.

Quick examples

Example: 1 J = 0.00027778 Wh.

Value (J)Result (Wh)
10.00027778
12.50.00347222
500.01388889
1000.02777778

Common mistakes and definitions

  • Rounding too early (convert first, then round at the end).
  • Mixing similar-looking symbols (for example, “m” vs “mm”, or “b” vs “B”).
  • Copying values without the unit symbol, which makes validation harder.

Common Conversions Table

Joule (J)Watt-hour (Wh)
10.00027778
20.00055556
30.00083333
50.00138889
100.00277778
250.00694444
500.01388889
1000.02777778
2500.06944444
5000.13888889
10000.27777778

Category facts

Smallest unit (on this site)
Electronvolt (eV)
Largest unit (on this site)
Gigaton (TNT) (Gton)

Popular conversions

Back to Energy category Browse more related converters below.

Joule → Watt-hourJoule → Kilowatt-hourKilojoule → KilocalorieCalorie → JouleBTU → JouleJoule → ElectronvoltJoule → Gram-force meterJoule → Kilojoule

Related conversions

Convert Joule to:
Watt-secondNewton-meterPound-force footFoot-poundCalorieCalorie (th)Calorie (IT)Pound-force inch
Convert to Watt-hour from:
KilocalorieFood CalorieKilocalorie (th)Calorie (nutritional, IT)Kilocalorie (IT)BTUBTU (IT)BTU (th)

FAQ

How to convert Joule to Watt-hour?
Enter the value in Joule, choose the target unit Watt-hour, and the result updates instantly. This page also includes the conversion formula and a quick reference table for verification.
What is the conversion formula from J to Wh?
Value in Wh = Value in J × 0.00027778
What is the smallest unit in Energy?
The smallest unit (as defined on this site) is: Electronvolt (eV). For higher precision, convert using a smaller unit first.
Why can results differ between websites?
Different standards, rounding rules, and unit definitions can change results. This page shows the formula used for transparency.
Are the results accurate?
Yes. Conversions run locally in your browser using verified ratios and display up to 8 decimals. Some categories like temperature and fuel use specialized formulas.

More Related Energy Tools

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Did you know?

Convert between Joules, Calories, BTU, and Watt-hours. Precision is the cornerstone of our platform. We utilize 15-digit floating-point arithmetic to ensure results meet 2026 industrial and academic verification standards. Looking for other types of calculations? Explore our Main Dashboard for 100,000+ precision permutations.