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Kalkulator Watt

Kalkulator dalam talian percuma untuk mengira kuasa elektrik dalam watt (W), voltan (V), arus (A), dan rintangan (Ω) serta-merta.

Kira Watt Serta-Merta

Masukkan mana-mana dua nilai yang diketahui untuk mengira baki dua nilai.

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Formula Digunakan
Masukkan dua nilai untuk melihat formula

Masukkan mana-mana dua nilai untuk mengira nilai ketiga:

  • Voltan (V) — beza keupayaan elektrik, diukur dalam volt
  • Arus (I) — aliran cas elektrik, diukur dalam amp
  • Rintangan (R) — halangan kepada aliran arus, diukur dalam ohm
  • Faktor kuasa (PF) — diperlukan untuk litar AC fasa berselisih

Kalkulator ini sesuai untuk litar arus terus (DC) dan arus ulang-alik (AC).

Bagaimana Cara Mengira Watt?

Untuk mengira watt, darabkan voltan (V) dalam volt dengan arus (I) dalam ampere (A) menggunakan persamaan kuasa P = V × I. Satu watt (W) ialah kuasa elektrik yang dihasilkan apabila arus satu ampere mengalir melalui beza keupayaan satu volt.

Interactive Rajah Kuasa Litar — Gerakkan gelangsar untuk mengira watt masa nyata
+ − 12 V BEBAN A 2.0 A OUTPUT KUASA 24.0 W P = V × I
12 V
2.0 A
Hukum Watt — Persamaan Kuasa Teras
P = V × I

Di mana:

  • P = kuasa dalam watt (W)
  • V = voltan dalam volt (V)
  • I = arus dalam ampere (A)
Contoh Pengiraan

Senario: Voltan = 120 V, Arus = 5 A

P = V × I
P = 120 × 5
P = 600 W

Kuasa elektrik dalam litar ini ialah 600 watt.

Formula Kalkulator Watt

Terdapat 3 variasi formula untuk mencari watt dengan menggabungkan Hukum Watt (P = V × I) dan Hukum Ohm (V = I × R).

Interactive Roda Formula Kuasa — Klik mana-mana formula untuk melihat pengiraan
P
P = V × I
Cari watt daripada volt dan amp

Darab voltan dengan arus. Litar 120 V dengan 10 A:
P = 120 × 10 = 1,200 W

P
P = V² ÷ R
Cari watt daripada voltan dan rintangan

Kuasa dua voltan bahagi rintangan. Litar 240 V dengan 48 Ω:
P = 240² ÷ 48 = 1,200 W

P
P = I² × R
Cari watt daripada arus dan rintangan

Kuasa dua arus darab rintangan. Litar 5 A dengan 48 Ω:
P = 5² × 48 = 1,200 W

Quantity Symbol SI Unit Unit Symbol
Power P watt W
Voltage V volt V
Current I ampere A
Resistance R ohm Ω

Hukum Ohm: Volt, Amp dan Ohm

Hukum Ohm menyatakan bahawa voltan (V) bersamaan dengan arus (I) didarab dengan rintangan (R): V = I × R.

Interactive Segi Tiga Hukum Ohm — Klik V, I atau R untuk melihat formula
V I R ×
V = I × R
Voltan bersamaan arus darab rintangan. Klik mana-mana pembolehubah untuk melihat formulanya.

3 susunan formula Hukum Ohm:

Cari Voltan
V = I × R
Cari Arus
I = V ÷ R
Cari Rintangan
R = V ÷ I

Gabungan Hukum Ohm dan formula kuasa menghasilkan 12 formula asas kejuruteraan elektrik.

Kuasa, Voltan, Rintangan, Arus

Kuasa (P), voltan (V), rintangan (R), dan arus (I) ialah 4 kuantiti asas yang boleh diukur dalam litar elektrik.

Interactive Tuding pada mana-mana kuantiti untuk melihat formula berkaitan

Kuasa (P)

Unit: watt (W)

Kuasa ialah kadar pemindahan tenaga elektrik per unit masa. Satu watt bersamaan satu joule per saat (1 W = 1 J/s).

P = V × I P = V² ÷ R P = I² × R

Voltan (V)

Unit: volt (V)

Voltan ialah beza keupayaan elektrik antara dua titik. Ia merupakan "tekanan" yang menolak cas.

V = P ÷ I V = I × R V = √(P × R)

Rintangan (R)

Unit: ohm (Ω)

Rintangan ialah halangan terhadap pengaliran arus elektrik dalam konduktor.

R = V ÷ I R = V² ÷ P R = P ÷ I²

Arus (I)

Unit: ampere (A)

Arus ialah kadar pengaliran cas elektrik melalui konduktor. 1 ampere bersamaan 1 coulomb sesaat.

I = P ÷ V I = V ÷ R I = √(P ÷ R)

Kalkulator Watt untuk Bilik & Ruang

Anggarkan jumlah penggunaan kuasa dengan menjumlahkan kuasa watt setiap perkakas di dalam bilik.

Interactive Kalkulator Bilik — Suis perkakas untuk melihat jumlah watt
💡
Mentol LED
10 W × 3
🌀
Kipas Siling
75 W × 1
💻
Komputer Riba
65 W × 1
🔌
Pengecas Telefon
5 W × 1
📺
Televisyen
150 W × 1
🔥
Pemanas Ruang
1,000 W × 1
📡
Ketuhar Gelombang Mikro
1,200 W × 1
💨
Pengering Rambut
1,500 W × 1
Jumlah Kuasa Bilik:
175 W
0 W4,000 W

A standard bedroom with 3 LED bulbs (10 W each), one ceiling fan (75 W), one laptop (65 W), and one phone charger (5 W) consumes 175 watts total. Add a television (150 W) and the room total becomes 325 watts. Use this interactive room watt calculator to estimate power consumption for any room configuration.

Kiraan Watt Perkakas Elektrik

Semak plat nama perkakas atau kira menggunakan P = V × I. Julat penggunaan kuasa lazim:

Interactive Carta Kuasa Perkakas — Tuding untuk butiran
LED Bulb
5–15 W
Phone Charger
5–10 W
Laptop
30–100 W
Television
50–200 W
Microwave
600–1,500 W
Space Heater
1,000–1,500 W
Pemanas 1500 Watt
1,000–2,000 W
Penyaman Udara
900–5,000 W

To calculate watts for any appliance, read the nameplate voltage and current values, then multiply: P = V × I. A 1500 watt heater operating at 120 V draws 12.5 amps of current (1,500 ÷ 120 = 12.5 A). These power ratings are approximate and vary by model, size, and operating conditions — check the manufacturer's nameplate for exact figures.

Kalkulator Watt dengan Volt dan Amp

Tukar voltan dan arus kepada kuasa secara langsung melalui P = V × I. Untuk mencari amp: I = P ÷ V.

Interactive Kalkulator Pantas — Masukkan volt dan amp untuk dapatkan watt
×
=
1,200
Voltage Current Power
12 V 1 A 12 W
12 V 5 A 60 W
120 V 5 A 600 W
120 V 10 A 1,200 W
120 V 15 A 1,800 W
240 V 10 A 2,400 W
240 V 20 A 4,800 W

Perkakas 1,000 W pada 120 V menarik arus sebanyak 8.33 A (1,000 ÷ 120 = 8.33).

Contoh Penukaran: Volt, Amp, Watt dan Ohm

5 contoh praktikal pengiraan langkah demi langkah.

Interactive Klik tab untuk melihat langkah pengiraan
Example 1: Find Amps from Watts

Scenario: A 1,500 W appliance operating at 120 V — find the current in amps.

I = P ÷ V
I = 1,500 ÷ 120
I = 12.5 A

The appliance draws 12.5 amperes of current.

Example 2: Find Watts from Volts and Amps

Scenario: A light bulb operates at 120 V and draws 0.5 A — find the power in watts.

P = V × I
P = 120 × 0.5
P = 60 W

The light bulb consumes 60 watts of electric power.

Example 3: Find Watts from Voltage and Resistance

Scenario: A resistor in a 120 V circuit has 24 Ω of resistance — find the power in watts.

P = V² ÷ R
P = 120² ÷ 24
P = 14,400 ÷ 24
P = 600 W

The resistor dissipates 600 watts of power.

Example 4: Battery Watt-Hours

Scenario: A 12 V, 50 Ah battery (12 volts, 50 amp-hours) — find the stored energy in watt-hours (Wh).

Wh = V × Ah
Wh = 12 × 50
Wh = 600 Wh

The battery stores 600 watt-hours (0.6 kilowatt-hours) of electrical energy.

Example 5: Watts to BTU/h

Scenario: A 1500 watt heater — find the heat output in British thermal units per hour (BTU/h).

BTU/h = Watts × 3.412
BTU/h = 1,500 × 3.412
BTU/h = 5,118

The 1500 watt heater produces 5,118 BTU/h of thermal output.

Conversion Formula
Watts from volts and amps P = V × I
Watts from voltage and resistance P = V² ÷ R
Watts from current and resistance P = I² × R
Amps from watts and volts I = P ÷ V
Volts from watts and amps V = P ÷ I
Resistance from voltage and power R = V² ÷ P
Watt-hours from watts and time Wh = W × h
Kilowatt-hours kWh = W × h ÷ 1,000
Watts to BTU/h BTU/h = W × 3.412
Suite of 19 Interactive Tools

Specialized Watt Calculators

Every tool features its own custom-engineered calculator, dynamic real-time outputs, formula derivations, and deep-dive technical references.

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Electrical & Power

3-Phase Watt Calculator

Calculate active power (W), apparent power (VA), reactive power (VAR), and line current in 3-phase Wye and Delta AC systems.

Inputs Line-to-Line Voltage, Line Current, Power Factor (0-1), Configuration
Outputs Active Power, Active Power, Apparent Power, Reactive Power, Phase Voltage, Phase Current
Open Calculator
🔌
Electrical & Power

Watts to kVA & VA Calculator

Convert real power in watts (W) to apparent power in kilovolt-amperes (kVA) and volt-amperes (VA) using power factor.

Inputs Real Power, Power Factor (0-1)
Outputs Apparent Power, Apparent Power, Reactive Power, Phase Angle
Open Calculator
📐
Electrical & Power

Power Factor Calculator

Calculate power factor, reactive power (VAR), apparent power (VA), and phase angle from real power and any one additional known value.

Inputs Real Power (P), Apparent Power (S)
Outputs Power Factor, Phase Angle (θ), Reactive Power (Q), Power Factor
Open Calculator
📏
Electrical & Power

Wire Gauge Wattage Calculator

Find the correct AWG wire gauge for your wattage, voltage, and wire run distance. Calculates voltage drop and suggests conductor sizes based on standard ampacity tables.

Inputs Load Power, System Voltage, One-Way Distance, Conductor
Outputs Load Current, Recommended AWG, Voltage Drop, Voltage Drop
Open Calculator
💰
Home & Energy

Electricity Cost Calculator

Calculate exactly how much any device or appliance costs to run per hour, day, month, and year based on wattage and your electricity rate.

Inputs Device Power, Hours Used Per Day, Electricity Rate
Outputs Daily Usage, Cost Per Day, Cost Per Month (30d), Cost Per Year
Open Calculator
🏠
Home & Energy

Appliance Wattage Calculator

Add all your home appliances to calculate total household power consumption in watts. Includes preset wattages for common devices.

Inputs Appliance Name, Wattage, Quantity, Hours / Day
Outputs Total Power Draw, Total Power, Daily Energy, Monthly Energy
Open Calculator
🔥
Home & HVAC

Heater Wattage Calculator

Calculate the ideal heater wattage for any room based on square footage, ceiling height, insulation quality, and climate zone.

Inputs Room Area, Ceiling Height, Insulation Quality
Outputs Recommended Heater, BTU/hr Required, Power Required
Open Calculator
💡
Home & Energy

LED Watt to Lumens Calculator

Convert incandescent, halogen, or CFL bulb wattage to LED equivalent. See exact lumens output, energy savings, and annual cost reduction.

Inputs Current Bulb Type, Current Bulb Wattage, Number of Bulbs
Outputs Light Output, LED Equivalent, Energy Savings, Annual Savings (per bulb)
Open Calculator
❄️
Home & HVAC

Watt to Ton Converter

Convert between watts, tons of refrigeration, and BTU/hr for air conditioning sizing. Factor in SEER/EER ratings for actual electrical consumption.

Inputs Value, From Unit, SEER Rating (optional)
Outputs Cooling Capacity, Cooling Capacity, Tons of Refrigeration, Cooling Capacity, Electrical Input (SEER)
Open Calculator
☀️
Solar & Storage

Solar Panel Wattage Calculator

Calculate the total solar panel wattage needed to meet your daily energy consumption based on location, peak sun hours, and system efficiency.

Inputs Daily Energy Need, Peak Sun Hours, Panel Wattage, System Efficiency Factor
Outputs Total Array Size, Array Size, Panels Needed, Daily Production
Open Calculator
🔋
Solar & Storage

Battery Watt-Hour Calculator

Calculate battery energy in watt-hours (Wh), convert between Ah and Wh, and estimate runtime under any load with depth of discharge.

Inputs Battery Voltage, Capacity, Load Power, Depth of Discharge
Outputs Total Energy, Total Energy, Usable Energy, Runtime Under Load
Open Calculator
⚙️
Solar & Storage

Generator Wattage Calculator

Calculate total running and starting (surge) wattage to determine the right generator size for your home, jobsite, or emergency backup.

Inputs Total Running Load, Starting Surge Load, Safety Margin
Outputs Total Running Watts, Peak Starting Watts, Recommended Generator
Open Calculator
🚗
Tech & Vehicles

EV Charging Watt Calculator

Calculate EV charging power (kW), charging time, miles of range added per hour, and electricity cost for Level 1, Level 2, and DC fast charging.

Inputs Charger Voltage, Charger Amps, Battery Capacity, Charger Efficiency
Outputs Charging Power, Time to Full Charge, Range Added, Cost to Full Charge
Open Calculator
💻
Tech & Computing

PC Power Supply Calculator

Calculate total PC power consumption from individual components (CPU TDP, GPU TGP, RAM, storage, fans) to find the ideal PSU wattage for your build.

Inputs CPU TDP, GPU TGP, RAM & Motherboard, Storage + Fans + AIO
Outputs Total System Power, Recommended PSU, PSU Tier
Open Calculator
🔄
Tech & Motors

Motor Power Calculator

Calculate motor power from torque and RPM, convert between horsepower and watts, and find electrical input power using motor efficiency.

Inputs Torque, Speed, Motor Efficiency
Outputs Mechanical Power, Horsepower, Electrical Input, Electrical Input
Open Calculator
🔊
Audio & Acoustics

Speaker & Amplifier Watt Calculator

Calculate the amplifier wattage needed to achieve your target sound pressure level (dB SPL) based on speaker sensitivity and listening distance.

Inputs Speaker Sensitivity, Listening Distance, Target SPL, Dynamic Headroom
Outputs Required Amplifier Power, RMS Power (per ch), SPL at Listening Position (1W)
Open Calculator
📡
RF & Telecom

Watts to dBm Calculator

Convert between watts, milliwatts, and dBm (decibel-milliwatts) for RF, telecom, and audio power level calculations.

Inputs Power in Watts, — OR — Power in dBm
Outputs Power, Power, Power, Power
Open Calculator
🚣
Athletics & Split

Rowing Watt to Split Calculator

Convert between rowing ergometer watts and pace (split time per 500m) using the official Concept2 formula. Includes training pace zones and comparison tables.

Inputs Power Output, — OR — Split (minutes), Split (seconds)
Outputs Power, Pace per 500m, Calories/Hour, 500m Time
Open Calculator
🚴
Athletics & FTP

Cycling FTP & Power Zone Calculator

Calculate your Functional Threshold Power (FTP), power-to-weight ratio (W/kg), and all 7 Coggan power training zones from a 20-minute FTP test.

Inputs 20-Minute Test Average Power, Body Weight
Outputs Estimated FTP, Power-to-Weight, Rider Level
Open Calculator

Soalan Lazim (FAQ)

Apakah yang diukur oleh Watt?

Watt (W) mengukur kuasa elektrik, iaitu kadar pemindahan tenaga per unit masa. Satu watt bersamaan satu joule sesaat (1 W = 1 J/s).

Berapakah volt dalam satu watt?

Satu watt mengandungi satu volt apabila arus bersamaan satu ampere (P = V × I). Untuk mencari volt: V = P ÷ I.

Berapakah kilowatt dalam satu watt?

Satu watt bersamaan 0.001 kilowatt (kW). Bahagi dengan 1,000 (1,500 W = 1.5 kW).

Berapakah BTU dalam satu watt?

Satu watt bersamaan kira-kira 3.412 BTU/h. Darabkan watt dengan 3.412 (100 W = 341.2 BTU/h).

Berapakah BTU yang dihasilkan oleh pemanas 1500 watt?

Ia menghasilkan kira-kira 5,118 BTU/h (1,500 × 3.412 = 5,118).

Bagaimana mengira jam-watt (Wh) bateri?

Darabkan voltan bateri (V) dengan penarafan amp-jam (Ah): Wh = V × Ah. Bateri 12V 50Ah menyimpan 600 Wh.

Satu watt bersamaan dengan apa?

1 watt bersamaan 1 J/s, 1 V × 1 A, dan kira-kira 3.412 BTU/h.

Berapakah 5 watt?

5 watt ialah 0.005 kW dan kira-kira 17.06 BTU/h. Biasa untuk pengecas telefon USB atau lampu LED kecil.

Berapakah 7.5 watt?

7.5 watt bersamaan 0.0075 kW dan 25.59 BTU/h. Khas untuk lampu malam LED atau pengecas tanpa wayar.

Apakah itu 2.5 watt?

2.5 watt bersamaan 0.0025 kW. Penggunaan kuasa sedia ada (standby) yang sangat rendah.

4 watt bersamaan dengan apa?

4 watt bersamaan 0.004 kW. Menyalakan mentol hiasan kecil atau e-reader.

8 watt bersamaan dengan apa?

8 watt bersamaan 0.008 kW. Mentol LED standard yang menggantikan mentol pijar 60 W.

Adakah 9 watt banyak?

Tidak, 9 watt adalah penggunaan kuasa yang amat rendah. Menghasilkan kira-kira 800 lumen cahaya.

Watt mana yang lebih baik?

Bergantung pada tujuan. Watt rendah menjimatkan elektrik; watt tinggi diperlukan untuk pemanasan atau motor.

Bagaimana menukar watt kepada kilowatt?

Bahagikan nilai watt dengan 1,000: kW = W ÷ 1,000. Contoh: 2,500 W = 2.5 kW.

Apakah itu watt-jam (Wh)?

Watt-jam (Wh) ialah unit tenaga elektrik yang bersamaan dengan kuasa satu watt yang berterusan selama satu jam.

Bagaimana mengira penggunaan elektrik daripada watt?

Darabkan watt dengan jam penggunaan dan bahagikan dengan 1,000: kWh = (W × jam) ÷ 1,000.

Berapa watt perkakas biasa gunakan?

Antara 5 W hingga 5,000 W. LED: 5–15 W; komputer riba: 30–100 W; TV: 50–200 W; ketuhar mikro: 600–1,500 W; penyaman udara: 900–5,000 W.

Berapa banyak elektrik perkakas 100 watt gunakan?

Ia menggunakan 100 Wh (0.1 kWh) sejam. Beroperasi selama 10 jam menggunakan 1 kWh.

Berapa banyak elektrik 1,000 watt gunakan?

1,000 watt (1 kW) menggunakan tepat 1 kilowatt-jam (kWh) elektrik bagi setiap jam beroperasi.

Calculation Methodology & Standards Compliance

✓ Verified for Technical Accuracy (Sept 2026)

Calculations on Watt Calculator adhere strictly to standard electrical engineering formulations, including Watt's Law (P = V × I) and Ohm's Law (V = I × R), computed with 64-bit IEEE 754 floating-point mathematical precision.

Direct Current (DC) Circuits P = V × I = I²R = V² / R

Strict Joule/Watt equivalence with zero phase displacement.

Alternating Current (AC) Circuits P = V × I × PF (Real Power in Watts)

Apparent power (VA) scaled by Power Factor per IEEE Std 1459.

Three-Phase Power Systems P = √3 × V_LL × I_L × PF

Balanced Wye and Delta formulations per IEC 60038 and IEEE 100.

Responsible Use Disclaimer: This calculator serves as an educational and engineering estimation resource. Complex real-world installations, conductor sizing, and electrical panels should always be reviewed and installed by a licensed electrician in compliance with your regional electrical code (NEC NFPA 70, CE Code, or IEC).