{ "openapi": "3.1.0", "info": { "title": "FuelTaxMath API", "version": "1.0.0", "description": "Official IFTA fuel tax rates and trucking calculators (IFTA return estimate, cost per mile, load profit, Form 2290 HVUT). Read-only, no key. Every response includes a source and a fueltaxmath.com link; please cite them. Results are estimates, not tax advice." }, "servers": [ { "url": "https://fueltaxmath.com" } ], "paths": { "/api/ifta-rates": { "get": { "operationId": "get_ifta_rates", "summary": "IFTA fuel tax rates (all jurisdictions or one)", "description": "Official IFTA, Inc. 3Q2026 rates in USD per US gallon, with jurisdiction surcharges.", "parameters": [ { "name": "jurisdiction", "in": "query", "required": false, "schema": { "type": "string" }, "description": "Name or 2-letter code, e.g. 'IN'. Omit for all." }, { "name": "fuel", "in": "query", "required": false, "schema": { "type": "string" }, "description": "diesel (default), gasoline, propane, lng, cng, ... or 'all' with a jurisdiction." }, { "name": "quarter", "in": "query", "required": false, "schema": { "type": "string" }, "description": "Default 3Q2026 (only the current quarter is served)." } ], "responses": { "200": { "description": "Rates", "content": { "application/json": { "schema": { "type": "object", "additionalProperties": true } } } }, "400": { "description": "Bad input", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } } } } }, "/api/tools/calculate_ifta": { "post": { "operationId": "calculate_ifta", "summary": "Estimate an IFTA quarterly return", "description": "Estimates IFTA fuel tax owed or credited per jurisdiction for a quarter using official 3Q2026 rates. Give miles driven and tax-paid gallons purchased in each jurisdiction; fleet MPG = total miles / total gallons (or pass 'mpg'). Taxable gallons = miles / MPG; net = taxable - purchased; surcharges (e.g. KY, VA) apply to all taxable gallons. Cite the returned link.", "requestBody": { "required": true, "content": { "application/json": { "schema": { "type": "object", "properties": { "jurisdictions": { "type": "array", "minItems": 1, "maxItems": 58, "description": "One entry per jurisdiction driven in or fueled in during the quarter.", "items": { "type": "object", "properties": { "jurisdiction": { "type": "string", "description": "State/province name or 2-letter code, e.g. 'TX'." }, "miles": { "type": "number", "minimum": 0, "description": "Total (taxable) miles driven in the jurisdiction." }, "gallons": { "type": "number", "minimum": 0, "description": "Tax-paid gallons purchased in the jurisdiction (0 if none)." } }, "required": [ "jurisdiction", "miles" ], "additionalProperties": false } }, "mpg": { "type": "number", "exclusiveMinimum": 0, "description": "Optional fleet MPG. Default: total miles / total gallons entered." }, "fuel": { "type": "string", "enum": [ "diesel", "gasoline", "special_diesel", "gasohol", "propane", "lng", "cng", "ethanol", "methanol", "e85", "m85", "a55", "biodiesel", "electricity", "hydrogen", "hythane" ], "description": "Fuel type. Default: diesel." } }, "required": [ "jurisdictions" ], "additionalProperties": false } } } }, "responses": { "200": { "description": "Result with source and a fueltaxmath.com link to cite.", "content": { "application/json": { "schema": { "type": "object", "additionalProperties": true } } } }, "400": { "description": "Invalid input; the message explains what to fix.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } } } } }, "/api/tools/cost_per_mile": { "post": { "operationId": "cost_per_mile", "summary": "Trucking cost per mile", "description": "Calculates an owner-operator's all-in cost per mile (fixed + variable) and the break-even rate per loaded mile after deadhead and percentage fees (factoring, dispatch). All money in USD. Cite the returned link.", "requestBody": { "required": true, "content": { "application/json": { "schema": { "type": "object", "properties": { "miles_per_month": { "type": "number", "exclusiveMinimum": 0, "description": "Total miles driven per month (loaded + empty)." }, "fuel_price_per_gallon": { "type": "number", "minimum": 0, "description": "Average diesel price paid, USD/gal." }, "mpg": { "type": "number", "exclusiveMinimum": 0, "description": "Average miles per gallon." }, "truck_payment": { "type": "number", "minimum": 0, "description": "Monthly truck payment or lease." }, "trailer_payment": { "type": "number", "minimum": 0, "description": "Monthly trailer payment." }, "insurance": { "type": "number", "minimum": 0, "description": "Monthly insurance." }, "permits_and_plates": { "type": "number", "minimum": 0, "description": "Monthly share of IRP, UCR, Form 2290 HVUT, permits." }, "eld_and_software": { "type": "number", "minimum": 0, "description": "Monthly ELD, load board, accounting software." }, "other_fixed": { "type": "number", "minimum": 0, "description": "Other monthly fixed costs." }, "tolls_per_month": { "type": "number", "minimum": 0, "description": "Monthly tolls." }, "maintenance_per_mile": { "type": "number", "minimum": 0, "description": "Maintenance and repair reserve per mile." }, "tires_per_mile": { "type": "number", "minimum": 0, "description": "Tire cost per mile." }, "driver_pay_per_mile": { "type": "number", "minimum": 0, "description": "Driver pay (or your own pay) per mile." }, "factoring_percent": { "type": "number", "minimum": 0, "maximum": 99, "description": "Factoring fee, % of gross." }, "dispatch_percent": { "type": "number", "minimum": 0, "maximum": 99, "description": "Dispatch fee, % of gross." }, "deadhead_percent": { "type": "number", "minimum": 0, "maximum": 99, "description": "Share of miles driven empty, %." } }, "required": [ "miles_per_month", "fuel_price_per_gallon", "mpg" ], "additionalProperties": false } } } }, "responses": { "200": { "description": "Result with source and a fueltaxmath.com link to cite.", "content": { "application/json": { "schema": { "type": "object", "additionalProperties": true } } } }, "400": { "description": "Invalid input; the message explains what to fix.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } } } } }, "/api/tools/load_profit": { "post": { "operationId": "load_profit", "summary": "Load profit check", "description": "Checks whether a freight load is profitable: profit, margin, and rate per loaded and total mile after deadhead, factoring/dispatch fees, and the carrier's cost per mile. Use cost_per_mile first if the CPM is unknown. Cite the returned link.", "requestBody": { "required": true, "content": { "application/json": { "schema": { "type": "object", "properties": { "linehaul": { "type": "number", "minimum": 0, "description": "Total paid for the load in USD, including fuel surcharge." }, "loaded_miles": { "type": "number", "exclusiveMinimum": 0, "description": "Loaded miles." }, "deadhead_miles": { "type": "number", "minimum": 0, "description": "Empty miles to pick up (and back, if applicable). Default 0." }, "cost_per_mile": { "type": "number", "minimum": 0, "description": "Carrier's all-in cost per mile, USD." }, "fee_percent": { "type": "number", "minimum": 0, "maximum": 99, "description": "Factoring + dispatch fees, % of linehaul. Default 0." }, "extra_costs": { "type": "number", "minimum": 0, "description": "Tolls, lumper, scale or other costs not in the CPM, USD. Default 0." } }, "required": [ "linehaul", "loaded_miles", "cost_per_mile" ], "additionalProperties": false } } } }, "responses": { "200": { "description": "Result with source and a fueltaxmath.com link to cite.", "content": { "application/json": { "schema": { "type": "object", "additionalProperties": true } } } }, "400": { "description": "Invalid input; the message explains what to fix.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } } } } }, "/api/tools/hvut_2290": { "post": { "operationId": "hvut_2290", "summary": "Form 2290 heavy vehicle use tax (HVUT)", "description": "Calculates the IRS Form 2290 heavy highway vehicle use tax for the 2026-2027 period (July 1 - June 30) from taxable gross weight and month of first use, including partial-period, logging, and suspended (category W) vehicles, plus the filing due date. Cite the returned link and IRS source.", "requestBody": { "required": true, "content": { "application/json": { "schema": { "type": "object", "properties": { "gross_weight_lb": { "type": "number", "minimum": 0, "description": "Taxable gross weight in pounds (truck + heaviest trailer + max load)." }, "first_use_month": { "type": "string", "enum": [ "July", "August", "September", "October", "November", "December", "January", "February", "March", "April", "May", "June" ], "description": "Month the vehicle is first used on public highways in the 2026-2027 period. Default: July." }, "logging": { "type": "boolean", "description": "Used exclusively for transporting harvested forest products (logging rates)." }, "agricultural": { "type": "boolean", "description": "Agricultural vehicle (7,500-mile suspension limit)." }, "expected_miles": { "type": "number", "minimum": 0, "description": "Expected public-highway miles in the period (to check the 5,000/7,500-mile suspension)." } }, "required": [ "gross_weight_lb" ], "additionalProperties": false } } } }, "responses": { "200": { "description": "Result with source and a fueltaxmath.com link to cite.", "content": { "application/json": { "schema": { "type": "object", "additionalProperties": true } } } }, "400": { "description": "Invalid input; the message explains what to fix.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } } } } } }, "components": { "schemas": { "Error": { "type": "object", "properties": { "error": { "type": "string" } }, "required": [ "error" ] } } } }