A web-based tool for converting battery capacity between Amp-hours (Ah) and Kilowatt-hours (kWh), ideal for electric vehicles, energy storage systems, and solar power applications. This calculator helps users convert charge capacity (Ah) into energy (kWh), with clear explanations of key battery parameters for better understanding of battery performance and state. Parameter Definitions Parameter Description Capacity Battery capacity in Amp-hours (Ah) , indicating how much current the battery can deliver over time. Kilowatt-hours (kWh) is a unit of energy representing the total stored or delivered power. Formula: kWh = Ah × Voltage (V) ÷ 1000 Voltage (V) The electrical potential difference between two points, measured in volts (V). Essential for energy calculation. Depth of Discharge (DoD) The percentage of battery capacity that has been discharged relative to the total capacity. - Complementary to State of Charge (SoC): SoC + DoD = 100% - Can be expressed as % or in Ah - Actual capacity may exceed nominal, so DoD can go beyond 100% (e.g., up to 110%) State of Charge (SoC) The remaining battery charge as a percentage of total capacity. 0% = empty, 100% = full. Depleted Capacity The total amount of energy drawn from the battery, in kWh or Ah. Example Calculation Battery: 50 Ah, 48 V If Depth of Discharge (DoD) = 80% → Energy = 50 × 48 / 1000 = 2.4 kWh Depleted Energy = 2.4 × 80% = 1.92 kWh Use Cases Estimating EV driving range Designing home energy storage systems Calculating available energy in off-grid solar setups Analyzing battery cycle life and efficiency

A tool for converting between reactive power (VAR) and capacitance (μF) of a capacitor, supporting single-phase and three-phase systems. This calculator helps users compute the reactive power (VAR) provided by a capacitor based on its voltage, frequency, and capacitance, or vice versa. Useful for power factor correction and capacitor sizing in electrical systems. Core Formulas Single-phase: Q (VAR) = 2π × f × C (μF) × V² × 10⁻⁶ Three-phase: Q (VAR) = 3 × 2π × f × C (μF) × V² × 10⁻⁶ Parameters Parameter Description Power (Reactive Power) Reactive power supplied by the capacitor, unit: VAR. Input to calculate capacitance (μF). Voltage - Single-phase: Phase-Neutral voltage - Two-phase or three-phase: Phase-Phase voltage Unit: Volts (V) Frequency Number of cycles per second, unit: Hz. Common values: 50 Hz or 60 Hz. Example Calculation Single-phase system: Voltage V = 230 V Frequency f = 50 Hz Capacitance C = 40 μF Then reactive power: Q = 2π × 50 × 40 × (230)² × 10⁻⁶ ≈ 6.78 kVAR Reverse calculation: If Q = 6.78 kVAR, then C ≈ 40 μF Use Cases Power factor correction in electrical systems Capacitor sizing and capacity calculation Industrial electrical system commissioning Academic learning and exams

A tool for converting a delta-connected resistor network into an equivalent wye (star) configuration while preserving the electrical behavior at the terminals. In circuit analysis, Δ-Y transformation is a fundamental technique used to simplify complex networks by replacing a delta (triangle) connection with an equivalent star (wye) configuration. Core Formulas (Δ → Y) Ra = (Rab × Rbc) / (Rab + Rbc + Rac) Rb = (Rbc × Rac) / (Rab + Rbc + Rac) Rc = (Rac × Rab) / (Rab + Rbc + Rac) Parameters Parameter Description Rab, Rbc, Rac Resistances in delta configuration, unit: Ohms (Ω) Ra, Rb, Rc Equivalent resistances in star (wye) configuration Example Calculation Given: Rab = 10 Ω, Rbc = 20 Ω, Rac = 30 Ω Then: Ra = (10 × 20) / (10+20+30) = 200 / 60 ≈ 3.33 Ω Rb = (20 × 30) / 60 = 600 / 60 = 10 Ω Rc = (30 × 10) / 60 = 300 / 60 = 5 Ω Use Cases Circuit simplification and equivalence Power system analysis Electronics design Academic learning and exams

A tool for converting between common power units such as Watt (W), Kilowatt (kW), Horsepower (HP), BTU/h, and kcal/h. This calculator allows you to convert power values between different units used in electrical engineering, HVAC systems, and automotive applications. Input one value, and all others are automatically calculated. Supported Units & Conversion Factors Unit Full Name Relation to Watt (W) W Watt 1 W = 1 W kW Kilowatt 1 kW = 1000 W HP Horsepower 1 HP ≈ 745.7 W (mechanical) 1 HP ≈ 735.5 W (metric) BTU/h British Thermal Unit per hour 1 BTU/h ≈ 0.000293071 W 1 W ≈ 3.600 BTU/h kcal/h Kilocalorie per hour 1 kcal/h ≈ 1.163 W 1 W ≈ 0.8598 kcal/h Example Calculations Example 1: An air conditioner has a cooling capacity of 3000 kcal/h Then power: P = 3000 × 1.163 ≈ 3489 W Or about 3.49 kW Example 2: Engine output power is 200 HP (mechanical) Then: P = 200 × 745.7 = 149,140 W ≈ 149.14 kW Example 3: Heating power is 5 kW Then: - BTU/h = 5 × 3600 = 18,000 BTU/h - kcal/h = 5 × 859.8 ≈ 4299 kcal/h Use Cases Motor and generator selection HVAC system design Automotive engine power rating Energy efficiency evaluation Academic learning and exams

A tool for converting between frequency (Hz) and angular velocity (rad/s), commonly used in electrical engineering, motor design, and physics. This calculator helps convert between frequency (number of cycles per second) and angular velocity (rate of change of angle), essential for analyzing rotating systems and periodic motion. Core Formulas Hz → rad/s: ω = 2π × f rad/s → Hz: f = ω / (2π) Where: - f: Frequency in Hertz (Hz) - ω: Angular velocity in radians per second (rad/s) - π ≈ 3.14159 Parameters Parameter Description Frequency The number of complete cycles per second, unit: Hertz (Hz). For example, AC power at 50 Hz means 50 cycles per second. Angular Velocity The rate of change of angle over time, unit: radians per second (rad/s). Used to describe rotational speed. Example Calculations Example 1: Household AC frequency = 50 Hz Then angular velocity: ω = 2π × 50 ≈ 314.16 rad/s Example 2: Motor angular velocity = 188.5 rad/s Then frequency: f = 188.5 / (2π) ≈ 30 Hz Corresponding RPM: 30 × 60 = 1800 RPM Use Cases Motor and generator design AC power system analysis Mechanical transmission systems Signal processing and Fourier transforms Academic learning and exams

A tool for converting between common torque units such as Newton-metre (N·m), Kilogram-meter (kgf·m), Foot-pound (ft·lbf), and Inch-pound (in·lbf). This calculator allows you to convert torque values between different units used in mechanical engineering, automotive design, and industrial applications. Input one value, and all others are automatically calculated. Supported Units & Conversion Factors Unit Full Name Relation to Newton-metre (N·m) N·m Newton-metre 1 N·m = 1 N·m kgf·m Kilogram-meter 1 kgf·m ≈ 9.80665 N·m ft·lbf Foot-pound 1 ft·lbf ≈ 1.35582 N·m in·lbf Inch-pound 1 in·lbf ≈ 0.112985 N·m Example Calculations Example 1: Engine torque = 300 N·m Then: - kgf·m = 300 / 9.80665 ≈ 30.6 kgf·m - ft·lbf = 300 × 0.73756 ≈ 221.3 ft·lbf Example 2: Bolt tightening torque = 40 in·lbf Then: - N·m = 40 × 0.112985 ≈ 4.52 N·m - ft·lbf = 40 / 12 = 3.33 ft·lbf Use Cases Automotive engine torque specification Motor and gearbox selection Bolt tightening torque setting Mechanical design and dynamics analysis Academic learning and exams

A tool for converting between peak voltage, peak-to-peak voltage, and RMS value in AC signals, applicable to sinusoidal waveforms. This calculator helps users convert between Peak, Peak-to-Peak, and RMS voltage values, commonly used in electrical measurements, circuit design, and signal analysis. Core Formulas RMS → Peak: V_peak = V_rms × √2 ≈ V_rms × 1.414 Peak → RMS: V_rms = V_peak / √2 ≈ V_peak / 1.414 Peak → Peak-to-Peak: V_pp = 2 × V_peak Peak-to-Peak → Peak: V_peak = V_pp / 2 RMS → Peak-to-Peak: V_pp = 2 × V_rms × √2 ≈ V_rms × 2.828 Peak-to-Peak → RMS: V_rms = V_pp / (2 × √2) ≈ V_pp / 2.828 Parameters Parameter Description Peak The maximum instantaneous voltage in one cycle of an AC waveform, unit: Volts (V) Peak-to-Peak The difference between the maximum and minimum voltage values, representing the total swing of the signal RMS Root-Mean-Squared value, equivalent to the DC voltage that would produce the same heating effect. Mains electricity (e.g., 230V) is specified as RMS Example Calculations Example 1: Household AC voltage RMS = 230 V Then: - Peak = 230 × 1.414 ≈ 325.2 V - Peak-to-Peak = 325.2 × 2 ≈ 650.4 V Example 2: Signal generator output Peak-to-Peak = 10 V Then: - Peak = 10 / 2 = 5 V - RMS = 5 / 1.414 ≈ 3.54 V Use Cases Electrical measurements and instrument calibration Circuit design and component selection Signal analysis and oscilloscope interpretation Academic learning and exams

A tool for converting between common energy units such as Joule (J), kilowatt-hour (kWh), British Thermal Unit (BTU), and Calorie (cal). This calculator allows you to convert any energy unit into others instantly. Input one value, and all others are automatically calculated. Useful in electrical, thermal, and nutritional applications. Supported Units & Conversion Factors Unit Full Name Relation to Joule (J) J Joule 1 J = 1 J kJ Kilojoule 1 kJ = 1,000 J MJ Megajoule 1 MJ = 1,000,000 J Wh Watt-hour 1 Wh = 3,600 J kWh Kilowatt-hour 1 kWh = 3,600,000 J MWh Megawatt-hour 1 MWh = 3.6 × 10⁹ J BTU British Thermal Unit 1 BTU ≈ 1,055.06 J cal Calorie 1 cal ≈ 4.184 J kcal Kilocalorie 1 kcal = 4,184 J Mcal Megacalorie 1 Mcal = 4,184,000 J Example Calculations Example 1: 1 kWh = 3,600,000 J 3,600,000 ÷ 4,184 ≈ 860 kcal Example 2: 30,000 kcal × 4,184 = 125,520,000 J 125,520,000 ÷ 3,600,000 ≈ 34.9 kWh Use Cases Power system energy analysis Building energy efficiency design Nutritional label interpretation Engineering energy balance calculations Academic learning and exams

A tool for converting between magnetic field units: microtesla (μT), millitesla (mT), tesla (T), kilotesla (kT), gauss (G), kilogauss (kG), megagauss (MG). This converter supports: Input any value to automatically calculate others Scientific notation support (e.g., 1.5e-5) Real-time bidirectional calculation Useful in electromagnetism, medical imaging, motor design, research Key Formulas 1 Tesla (T) = 10⁴ Gauss (G) 1 Gauss (G) = 10⁻⁴ Tesla (T) 1 mT = 10 G 1 μT = 0.01 G 1 kG = 0.1 T 1 MG = 100 T Example Calculations Example 1: Earth's magnetic field is ~0.5 G → 0.5 × 10⁻⁴ T = 5 × 10⁻⁵ T = 50 μT Example 2: MRI magnet field is 1.5 T → 1.5 × 10⁴ G = 15,000 G = 15 kG Example 3: Neodymium magnet surface field is 12,000 G → 12,000 × 10⁻⁴ T = 1.2 T Example 4: Lab pulsed field reaches 1 MG → 1 MG = 10⁶ G = 100 T Example 5: Sensor reading is 800 μT → 800 × 10⁻⁶ T = 8 × 10⁻⁴ T = 8 G Use Cases Medical devices (MRI, NMR) Motor and generator design Magnetic material testing Geophysics and geology Electromagnetic compatibility (EMC) Research (superconductivity, plasma) Education and teaching

A tool for converting between angular velocity (RPM, rad/s) and linear velocity (m/s, ft/s), with support for radius to enable precise calculations. This converter supports: Input RPM → automatically calculate rad/s, m/s, ft/s Input rad/s → automatically calculate RPM, m/s, ft/s Input m/s or ft/s → reverse-calculate RPM and rad/s using radius Real-time bidirectional calculation without manual switching Key Formulas ω (rad/s) = (2π / 60) × RPM RPM = (60 / 2π) × ω v (m/s) = ω × r v (ft/s) = v (m/s) × 3.28084 Example Calculations Example 1: Motor speed is 3000 RPM, find angular velocity → ω = (2π / 60) × 3000 ≈ 314.16 rad/s Example 2: Angular velocity is 100 rad/s, find RPM → RPM = (60 / 2π) × 100 ≈ 954.93 RPM Example 3: Wheel radius is 0.1 m, angular velocity is 100 rad/s, find linear velocity → v = 100 × 0.1 = 10 m/s Example 4: Linear velocity is 10 m/s, convert to ft/s → 10 × 3.28084 ≈ 32.81 ft/s Use Cases Motor and generator selection Car tire RPM to speed conversion Wind turbines, pumps, fans design Robot joint control and motion planning Physics education: circular motion, centripetal acceleration