{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"kva-kw-power-factor"},"result":{"entity_type":"calculator","id":"kva-kw-power-factor","calculator_id":"kva-kw-power-factor","canonical_url":"https://tttkmbb.com/engineering/kva-kw-power-factor","name":"kVA, kW and Power Factor Calculator","title":"kVA to kW Calculator – Apparent, Real and Reactive Power, Power Factor and Current from Any Two Values","category":"engineering","category_name":"Engineering & Automotive","tool_name":"convert_kva_kw_power_factor","featured_mcp_tool":false,"description":"Completes the AC power triangle from any two of apparent power (kVA), real power (kW), reactive power (kVAR) and power factor, reports the phase angle and, when a voltage is given, the single- or three-phase line current, plus the capacitor kVAR needed to correct the power factor to 0.95.","use_when":"You need to convert a transformer, generator or UPS kVA rating to usable kW, find the power factor or reactive power of a load, size a power-factor-correction capacitor bank, or get the current for a kVA load at a voltage.","do_not_use_when":"You have line voltage and current of a balanced three-phase load and want the full per-phase breakdown (use three-phase-power), or the load is DC or non-sinusoidal with strong harmonics (displacement and distortion power factor differ).","inputs":[{"name":"apparent_power_kva","label":"Apparent power S","type":"number","unit":"kVA","required":false,"max":10000000,"exclusive_min":0,"description":"Apparent power in kilovolt-amperes (the nameplate rating of transformers and generators).","example":100},{"name":"real_power_kw","label":"Real power P","type":"number","unit":"kW","required":false,"min":0,"max":10000000,"description":"Real (active) power in kilowatts, the part that does work and is billed as energy."},{"name":"power_factor","label":"Power factor","type":"number","required":false,"max":1,"exclusive_min":0,"description":"cos φ between 0 and 1 (typical: motors 0.8–0.9, resistive heaters 1.0).","example":0.8},{"name":"reactive_power_kvar","label":"Reactive power Q","type":"number","unit":"kVAR","required":false,"min":0,"max":10000000,"description":"Reactive power in kilovolt-amperes reactive (magnetising power of motors and transformers)."},{"name":"voltage_v","label":"Voltage","type":"number","unit":"V","required":false,"max":1000000,"exclusive_min":0,"description":"Optional RMS supply voltage (line-to-line for three-phase); enables the current output.","example":400},{"name":"phases","label":"Phases","type":"enum","required":false,"default":"three","values":[{"value":"single","label":"Single-phase: I = S / V","aliases":["1","single_phase","1ph"]},{"value":"three","label":"Three-phase: I = S / (√3 × V_LL)","aliases":["3","three_phase","3ph"]}],"description":"Supply type used for the current calculation.","example":"three"}],"outputs":[{"name":"apparent_power_kva","label":"Apparent power S","type":"number","unit":"kVA","decimals":3,"description":"S = √(P² + Q²) = P / PF."},{"name":"real_power_kw","label":"Real power P","type":"number","unit":"kW","decimals":3,"description":"P = S × PF."},{"name":"reactive_power_kvar","label":"Reactive power Q","type":"number","unit":"kVAR","decimals":3,"description":"Q = √(S² − P²)."},{"name":"power_factor","label":"Power factor","type":"number","decimals":4,"description":"PF = P / S = cos φ."},{"name":"phase_angle_degrees","label":"Phase angle φ","type":"number","unit":"°","decimals":2,"description":"φ = arccos(PF), the angle between voltage and current."},{"name":"current_a","label":"Line current","type":"number","unit":"A","decimals":3,"description":"I = S × 1000 / V (single-phase) or S × 1000 / (√3 × V) (three-phase); only when voltage_v is given."},{"name":"kvar_to_reach_pf_0_95","label":"Capacitor kVAR for PF 0.95","type":"number","unit":"kVAR","decimals":3,"description":"Reactive compensation needed to raise the power factor to 0.95: Q − P × tan(arccos 0.95); 0 when PF is already 0.95 or higher."},{"name":"pf_correction_note","label":"Power-factor correction","type":"string","decimals":4,"description":"Plain-language note on correcting the power factor to the common 0.95 target (lagging load assumed)."},{"name":"given","label":"Given quantities","type":"string","decimals":4,"description":"Which two inputs the triangle was solved from."}],"input_schema":{"type":"object","properties":{"apparent_power_kva":{"description":"Apparent power in kilovolt-amperes (the nameplate rating of transformers and generators). Unit: kVA.","type":"number","maximum":10000000,"exclusiveMinimum":0,"examples":[100],"x-unit":"kVA"},"real_power_kw":{"description":"Real (active) power in kilowatts, the part that does work and is billed as energy. Unit: kW.","type":"number","minimum":0,"maximum":10000000,"x-unit":"kW"},"power_factor":{"description":"cos φ between 0 and 1 (typical: motors 0.8–0.9, resistive heaters 1.0).","type":"number","maximum":1,"exclusiveMinimum":0,"examples":[0.8]},"reactive_power_kvar":{"description":"Reactive power in kilovolt-amperes reactive (magnetising power of motors and transformers). Unit: kVAR.","type":"number","minimum":0,"maximum":10000000,"x-unit":"kVAR"},"voltage_v":{"description":"Optional RMS supply voltage (line-to-line for three-phase); enables the current output. Unit: V.","type":"number","maximum":1000000,"exclusiveMinimum":0,"examples":[400],"x-unit":"V"},"phases":{"description":"Supply type used for the current calculation.","type":"string","enum":["single","three"],"default":"three","examples":["three"]}},"additionalProperties":false},"output_schema":{"type":"object","properties":{"apparent_power_kva":{"description":"S = √(P² + Q²) = P / PF. Unit: kVA.","type":"number","x-unit":"kVA"},"real_power_kw":{"description":"P = S × PF. Unit: kW.","type":"number","x-unit":"kW"},"reactive_power_kvar":{"description":"Q = √(S² − P²). Unit: kVAR.","type":"number","x-unit":"kVAR"},"power_factor":{"description":"PF = P / S = cos φ.","type":"number"},"phase_angle_degrees":{"description":"φ = arccos(PF), the angle between voltage and current. Unit: °.","type":"number","x-unit":"°"},"current_a":{"description":"I = S × 1000 / V (single-phase) or S × 1000 / (√3 × V) (three-phase); only when voltage_v is given. Unit: A.","type":"number","x-unit":"A"},"kvar_to_reach_pf_0_95":{"description":"Reactive compensation needed to raise the power factor to 0.95: Q − P × tan(arccos 0.95); 0 when PF is already 0.95 or higher. Unit: kVAR.","type":"number","x-unit":"kVAR"},"pf_correction_note":{"description":"Plain-language note on correcting the power factor to the common 0.95 target (lagging load assumed).","type":"string"},"given":{"description":"Which two inputs the triangle was solved from.","type":"string"}}},"formula":"S² = P² + Q²; PF = P / S; φ = arccos(PF); from S and PF: P = S × PF, Q = √(S² − P²); from P and Q: S = √(P² + Q²); from P and PF: S = P / PF; from PF and Q: S = Q / √(1 − PF²); current_a = S × 1000 / voltage_v (single) or S × 1000 / (√3 × voltage_v) (three); kvar_to_reach_pf_0_95 = max(0, Q − P × tan(arccos 0.95))","method":"Power-triangle relations for sinusoidal AC (displacement power factor). The load is assumed inductive (lagging), which is the usual case for motors and transformers; a leading (capacitive) load has the same magnitudes with the opposite sign of Q.","sources":[{"name":"Wikipedia – AC power (power triangle)","url":"https://en.wikipedia.org/wiki/AC_power","type":"reference","retrieved_at":"2026-09-24"},{"name":"Wikipedia – Power factor","url":"https://en.wikipedia.org/wiki/Power_factor","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"100 kVA at PF 0.8, 400 V three-phase","inputs":{"apparent_power_kva":100,"power_factor":0.8,"voltage_v":400,"phases":"three"},"expected":{"apparent_power_kva":100,"real_power_kw":80,"reactive_power_kvar":60,"power_factor":0.8,"phase_angle_degrees":36.87,"current_a":144.338,"kvar_to_reach_pf_0_95":33.705},"url":"https://tttkmbb.com/api/v1/calculate/kva-kw-power-factor?apparent_power_kva=100&power_factor=0.8&voltage_v=400&phases=three"},{"name":"50 kW and 30 kVAR","inputs":{"real_power_kw":50,"reactive_power_kvar":30},"expected":{"apparent_power_kva":58.31,"power_factor":0.8575,"phase_angle_degrees":30.96,"kvar_to_reach_pf_0_95":13.566},"url":"https://tttkmbb.com/api/v1/calculate/kva-kw-power-factor?real_power_kw=50&reactive_power_kvar=30"}],"faq":[{"q":"Why is kVA larger than kW?","a":"Real power is only the component of the apparent power in phase with the voltage; the remaining reactive power circulates between source and load without doing work but still loads conductors and transformers. kW = kVA only at power factor 1."},{"q":"How much capacitor kVAR do I need for correction?","a":"The load's reactive power minus the reactive power allowed at the target factor: Q_c = P × (tan φ₁ − tan φ₂). For 80 kW at PF 0.8 corrected to 0.95 that is 60 − 26.3 ≈ 33.7 kVAR."},{"q":"Why can I not enter PF 1 with a reactive power?","a":"At unity power factor the reactive power is zero by definition, so the pair is contradictory; give real or apparent power instead."}],"tags":["kva to kw","kw to kva","power factor calculator","reactive power kvar","power triangle","power factor correction"],"related":[{"calculator_id":"three-phase-power","reason":"Full per-phase breakdown for balanced three-phase loads."},{"calculator_id":"electric-power","reason":"P = V × I for DC and unity power factor."},{"calculator_id":"wire-voltage-drop","reason":"Cable drop for the resulting current."}],"links":{"html":"https://tttkmbb.com/engineering/kva-kw-power-factor","markdown":"https://tttkmbb.com/engineering/kva-kw-power-factor.md","json":"https://tttkmbb.com/engineering/kva-kw-power-factor.json","api":"https://tttkmbb.com/api/v1/calculate/kva-kw-power-factor","schema":"https://tttkmbb.com/api/v1/calculators/kva-kw-power-factor","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T03:44:39Z"}