{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"fuel-economy"},"result":{"entity_type":"calculator","id":"fuel-economy","calculator_id":"fuel-economy","canonical_url":"https://tttkmbb.com/conversion/fuel-economy","name":"Fuel Economy Converter","title":"Fuel Economy Converter – L/100km, km/L, US MPG and UK (Imperial) MPG","category":"conversion","category_name":"Unit Conversion","tool_name":"convert_fuel_economy","featured_mcp_tool":false,"description":"Converts fuel consumption between litres per 100 km, kilometres per litre, miles per US gallon and miles per imperial gallon; L/100km is the base and the mpg relations are reciprocal (L/100km = 235.214583 / mpg_US).","use_when":"You need a car's fuel economy in another convention, e.g. mpg to L/100km, L/100km to km/L or US mpg to UK mpg.","do_not_use_when":"You need the fuel cost of a trip (use fuel-cost) or plain volume or distance conversions (use volume, length).","inputs":[{"name":"value","label":"Value","type":"number","required":true,"exclusive_min":0,"description":"Fuel economy in from_unit (must be greater than 0).","example":30},{"name":"from_unit","label":"From unit","type":"enum","required":true,"values":[{"value":"L/100km","label":"Litres per 100 km (L/100km)","aliases":["litres per 100 km","litres-per-100-km","litresper100km","litres·per·100·km","litres_per_100_km","liters per 100 km","liters-per-100-km","litersper100km","liters·per·100·km","liters_per_100_km","l/100 km","l/100-km","l/100·km","l/100_km","litres per 100 kilometres","litres-per-100-kilometres","litresper100kilometres","litres·per·100·kilometres","litres_per_100_kilometres","liters per 100 kilometers","liters-per-100-kilometers","litersper100kilometers","liters·per·100·kilometers","liters_per_100_kilometers","l per 100 km","l-per-100-km","lper100km","l·per·100·km","l_per_100_km"]},{"value":"km/L","label":"Kilometres per litre (km/L)","aliases":["kilometres per litre","kilometres-per-litre","kilometresperlitre","kilometres·per·litre","kilometres_per_litre","kilometers per liter","kilometers-per-liter","kilometersperliter","kilometers·per·liter","kilometers_per_liter","km per litre","km-per-litre","kmperlitre","km·per·litre","km_per_litre","km per liter","km-per-liter","kmperliter","km·per·liter","km_per_liter","kpl"]},{"value":"mpg_us","label":"Miles per US gallon (mpg_us)","aliases":["mpg-us","mpg us","mpgus","mpg·us","miles per us gallon","miles-per-us-gallon","milesperusgallon","miles·per·us·gallon","miles_per_us_gallon","mpg","mpg (us)","mpg-(us)","mpg(us)","mpg·(us)","mpg_(us)","us mpg","us-mpg","usmpg","us·mpg","us_mpg","miles per gallon","miles-per-gallon","milespergallon","miles·per·gallon","miles_per_gallon","miles per gallon (us)","miles-per-gallon-(us)","milespergallon(us)","miles·per·gallon·(us)","miles_per_gallon_(us)","mi/gal"]},{"value":"mpg_uk","label":"Miles per imperial gallon (mpg_uk)","aliases":["mpg-uk","mpg uk","mpguk","mpg·uk","miles per imperial gallon","miles-per-imperial-gallon","milesperimperialgallon","miles·per·imperial·gallon","miles_per_imperial_gallon","mpg (uk)","mpg-(uk)","mpg(uk)","mpg·(uk)","mpg_(uk)","uk mpg","uk-mpg","ukmpg","uk·mpg","uk_mpg","imperial mpg","imperial-mpg","imperialmpg","imperial·mpg","imperial_mpg","mpg imp","mpg-imp","mpgimp","mpg·imp","mpg_imp","miles per gallon (uk)","miles-per-gallon-(uk)","milespergallon(uk)","miles·per·gallon·(uk)","miles_per_gallon_(uk)"]}],"description":"Unit of the input value. Accepted symbols: L/100km, km/L, mpg_us, mpg_uk; spelled-out names and common abbreviations are accepted too.","example":"mpg_us"},{"name":"to_unit","label":"To unit","type":"enum","required":true,"values":[{"value":"L/100km","label":"Litres per 100 km (L/100km)","aliases":["litres per 100 km","litres-per-100-km","litresper100km","litres·per·100·km","litres_per_100_km","liters per 100 km","liters-per-100-km","litersper100km","liters·per·100·km","liters_per_100_km","l/100 km","l/100-km","l/100·km","l/100_km","litres per 100 kilometres","litres-per-100-kilometres","litresper100kilometres","litres·per·100·kilometres","litres_per_100_kilometres","liters per 100 kilometers","liters-per-100-kilometers","litersper100kilometers","liters·per·100·kilometers","liters_per_100_kilometers","l per 100 km","l-per-100-km","lper100km","l·per·100·km","l_per_100_km"]},{"value":"km/L","label":"Kilometres per litre (km/L)","aliases":["kilometres per litre","kilometres-per-litre","kilometresperlitre","kilometres·per·litre","kilometres_per_litre","kilometers per liter","kilometers-per-liter","kilometersperliter","kilometers·per·liter","kilometers_per_liter","km per litre","km-per-litre","kmperlitre","km·per·litre","km_per_litre","km per liter","km-per-liter","kmperliter","km·per·liter","km_per_liter","kpl"]},{"value":"mpg_us","label":"Miles per US gallon (mpg_us)","aliases":["mpg-us","mpg us","mpgus","mpg·us","miles per us gallon","miles-per-us-gallon","milesperusgallon","miles·per·us·gallon","miles_per_us_gallon","mpg","mpg (us)","mpg-(us)","mpg(us)","mpg·(us)","mpg_(us)","us mpg","us-mpg","usmpg","us·mpg","us_mpg","miles per gallon","miles-per-gallon","milespergallon","miles·per·gallon","miles_per_gallon","miles per gallon (us)","miles-per-gallon-(us)","milespergallon(us)","miles·per·gallon·(us)","miles_per_gallon_(us)","mi/gal"]},{"value":"mpg_uk","label":"Miles per imperial gallon (mpg_uk)","aliases":["mpg-uk","mpg uk","mpguk","mpg·uk","miles per imperial gallon","miles-per-imperial-gallon","milesperimperialgallon","miles·per·imperial·gallon","miles_per_imperial_gallon","mpg (uk)","mpg-(uk)","mpg(uk)","mpg·(uk)","mpg_(uk)","uk mpg","uk-mpg","ukmpg","uk·mpg","uk_mpg","imperial mpg","imperial-mpg","imperialmpg","imperial·mpg","imperial_mpg","mpg imp","mpg-imp","mpgimp","mpg·imp","mpg_imp","miles per gallon (uk)","miles-per-gallon-(uk)","milespergallon(uk)","miles·per·gallon·(uk)","miles_per_gallon_(uk)"]}],"description":"Unit to convert into (same symbols as from_unit).","example":"L/100km"}],"outputs":[{"name":"result","label":"Result","type":"number","decimals":6,"description":"Converted value expressed in to_unit (rounded to 6 decimals; see result_text for very small or very large values)."},{"name":"result_text","label":"Conversion","type":"string","decimals":4,"description":"The conversion as text with 6 significant figures, e.g. \"5 mi = 8.04672 km\"."},{"name":"formula","label":"Unit relation","type":"string","decimals":4,"description":"Relation used, e.g. \"1 mi = 1.609344 km\"."},{"name":"factor","label":"Factor","type":"number","decimals":12,"description":"Multiplier from from_unit to to_unit (result = value × factor); absent for non-linear conversions."},{"name":"conversion_table","label":"Conversion table","type":"object","decimals":12,"description":"The input value expressed in every supported fuel economy unit (6 significant figures), keyed by unit symbol."}],"input_schema":{"type":"object","properties":{"value":{"description":"Fuel economy in from_unit (must be greater than 0).","type":"number","exclusiveMinimum":0,"examples":[30]},"from_unit":{"description":"Unit of the input value. Accepted symbols: L/100km, km/L, mpg_us, mpg_uk; spelled-out names and common abbreviations are accepted too.","type":"string","enum":["L/100km","km/L","mpg_us","mpg_uk"],"examples":["mpg_us"]},"to_unit":{"description":"Unit to convert into (same symbols as from_unit).","type":"string","enum":["L/100km","km/L","mpg_us","mpg_uk"],"examples":["L/100km"]}},"additionalProperties":false,"required":["value","from_unit","to_unit"]},"output_schema":{"type":"object","properties":{"result":{"description":"Converted value expressed in to_unit (rounded to 6 decimals; see result_text for very small or very large values).","type":"number"},"result_text":{"description":"The conversion as text with 6 significant figures, e.g. \"5 mi = 8.04672 km\".","type":"string"},"formula":{"description":"Relation used, e.g. \"1 mi = 1.609344 km\".","type":"string"},"factor":{"description":"Multiplier from from_unit to to_unit (result = value × factor); absent for non-linear conversions.","type":"number"},"conversion_table":{"description":"The input value expressed in every supported fuel economy unit (6 significant figures), keyed by unit symbol.","type":"object"}}},"formula":"L/100km = 100 / (km/L) = 235.214583 / mpg(US) = 282.480936 / mpg(UK); mpg(UK) = mpg(US) × 1.200950","method":"Consumption (L/100km) and economy (km/L, mpg) are reciprocals, so the conversion is non-linear and no constant factor applies. Constants: 100 × 3.785411784 / 1.609344 = 235.214583 and 100 × 4.54609 / 1.609344 = 282.480936.","sources":[{"name":"NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors","url":"https://www.nist.gov/pml/special-publication-811","type":"standard","retrieved_at":"2026-09-23"},{"name":"Wikipedia – Fuel economy in automobiles (units and conversions)","url":"https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles","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":"30 US mpg to L/100km","inputs":{"value":30,"from_unit":"mpg_us","to_unit":"L/100km"},"expected":{"result":7.840486,"formula":"L/100km = 235.214583 / mpg (US)","conversion_table":{"km/L":12.7543,"mpg_uk":36.0285}},"url":"https://tttkmbb.com/api/v1/calculate/fuel-economy?value=30&from_unit=mpg_us&to_unit=L%2F100km"},{"name":"6 L/100km to US mpg","inputs":{"value":6,"from_unit":"L/100km","to_unit":"mpg_us"},"expected":{"result":39.202431,"conversion_table":{"km/L":16.6667,"mpg_uk":47.0802}},"url":"https://tttkmbb.com/api/v1/calculate/fuel-economy?value=6&from_unit=L%2F100km&to_unit=mpg_us"}],"faq":[{"q":"Which mpg does 'mpg' mean?","a":"The plain alias mpg resolves to miles per US gallon (mpg_us). UK figures use the larger imperial gallon: mpg_uk = mpg_us × 1.20095."},{"q":"Why is lower L/100km better?","a":"L/100km measures consumption, mpg and km/L measure economy; 5 L/100km = 20 km/L = 47.0 US mpg, and halving consumption doubles mpg."}],"tags":["fuel economy converter","mpg to l/100km","l/100km to mpg","km per litre","uk mpg to us mpg"],"related":[{"calculator_id":"fuel-cost","reason":"Trip fuel cost from distance, consumption and price."},{"calculator_id":"volume","reason":"Convert gallons and litres directly."},{"calculator_id":"length","reason":"Convert miles and kilometres directly."}],"links":{"html":"https://tttkmbb.com/conversion/fuel-economy","markdown":"https://tttkmbb.com/conversion/fuel-economy.md","json":"https://tttkmbb.com/conversion/fuel-economy.json","api":"https://tttkmbb.com/api/v1/calculate/fuel-economy","schema":"https://tttkmbb.com/api/v1/calculators/fuel-economy","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-23"},"timestamp":"2026-09-23T23:31:45Z"}