{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"ohms-law"},"result":{"entity_type":"calculator","id":"ohms-law","calculator_id":"ohms-law","canonical_url":"https://tttkmbb.com/physics/ohms-law","name":"Ohm's Law Calculator","title":"Ohm's Law Calculator – Solve V = I·R for Voltage, Current or Resistance, with Power","category":"physics","category_name":"Physics","tool_name":"solve_ohms_law","featured_mcp_tool":true,"description":"Solves Ohm's law V = I·R for whichever of voltage, current or resistance is omitted and reports the electrical power dissipated (P = V·I).","use_when":"You know two of voltage, current and resistance in a DC or purely resistive circuit and need the third and the power.","do_not_use_when":"The load is reactive (inductors or capacitors require impedance, not resistance), you want energy cost over time (use electric-power), or you need the equivalent resistance of several resistors (use resistors-series-parallel).","inputs":[{"name":"voltage_v","label":"Voltage","type":"number","unit":"V","required":false,"min":0,"description":"Potential difference across the component in volts. Omit to solve for it.","example":12},{"name":"current_a","label":"Current","type":"number","unit":"A","required":false,"min":0,"description":"Current through the component in amperes (1 mA = 0.001 A). Omit to solve for it."},{"name":"resistance_ohm","label":"Resistance","type":"number","unit":"Ω","required":false,"exclusive_min":0,"description":"Resistance in ohms (1 kΩ = 1000 Ω). 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Unit: W.","type":"number","x-unit":"W"}}},"formula":"V = I × R; I = V / R; R = V / I; P = V × I = I² × R = V² / R","sources":[{"name":"HyperPhysics – Ohm's law","url":"http://hyperphysics.phy-astr.gsu.edu/hbase/electric/ohmlaw.html","type":"reference","retrieved_at":"2026-09-23"},{"name":"Wikipedia – Ohm's law","url":"https://en.wikipedia.org/wiki/Ohm%27s_law","type":"reference","retrieved_at":"2026-09-23"}],"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":"12 V across 220 Ω","inputs":{"voltage_v":12,"resistance_ohm":220},"expected":{"solved_for":"current_a","current_a":0.054545,"current_ma":54.545,"power_w":0.6545},"url":"https://tttkmbb.com/api/v1/calculate/ohms-law?voltage_v=12&resistance_ohm=220"},{"name":"2 A through 50 Ω","inputs":{"current_a":2,"resistance_ohm":50},"expected":{"solved_for":"voltage_v","voltage_v":100,"power_w":200},"url":"https://tttkmbb.com/api/v1/calculate/ohms-law?current_a=2&resistance_ohm=50"}],"faq":[{"q":"Does Ohm's law apply to AC circuits?","a":"Only for purely resistive loads. With inductance or capacitance the relation becomes V = I·Z with complex impedance Z, and the power depends on the phase angle."},{"q":"Why does the power matter?","a":"A resistor must be rated above the dissipated power (e.g. 0.65 W needs at least a 1 W resistor) or it overheats."}],"tags":["ohm's law","voltage current resistance","v = ir","resistor","electrical power"],"related":[{"calculator_id":"electric-power","reason":"Power, energy and running cost of an appliance."},{"calculator_id":"resistors-series-parallel","reason":"Equivalent resistance of several resistors."}],"links":{"html":"https://tttkmbb.com/physics/ohms-law","markdown":"https://tttkmbb.com/physics/ohms-law.md","json":"https://tttkmbb.com/physics/ohms-law.json","api":"https://tttkmbb.com/api/v1/calculate/ohms-law","schema":"https://tttkmbb.com/api/v1/calculators/ohms-law","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-23"},"timestamp":"2026-09-23T23:29:04Z"}