Compare two driving routes

How route time and fuel cost are computed for each option

Driving time in hours equals distance divided by average speed when speed is expressed in distance units per hour—miles per hour with miles, or kilometres per hour with kilometres. Fuel volume equals distance divided by fuel economy when economy is distance per unit of fuel, such as miles per gallon or kilometres per litre. Fuel cost is that volume multiplied by the price of one unit of fuel. The same economy and price apply to both routes so you isolate geometry and speed, not a change of car or pump. Keep units coherent across all six inputs—do not mix miles with kilometres per hour without converting first. Send required fields distance_a, average_speed_a, distance_b, average_speed_b, fuel_economy, and fuel_price as JSON numbers or numeric strings. Aliases dist_a, route_a_distance, and da map to distance_a; speed_a, avg_speed_a, and va map to average_speed_a; the same pattern applies to route B. Aliases economy, mpg, km_per_l, and efficiency map to fuel_economy; price, gas_price, and fuel_unit_price map to fuel_price. Non-positive distance, average speed, or fuel economy is rejected as invalid_input so the engine never divides by zero or invents a negative trip. Negative fuel_price is likewise invalid. Magnitude caps keep results finite on the Worker isolate. Identical inputs always produce identical JSON: pure arithmetic, no network, no random seed, and no wall clock.

Reading the comparison fields and choosing realistic inputs

Use the time fields when you care about appointment windows, school runs, or delivery service levels. Use the cost fields when you budget a holiday drive, reimburse fuel-only expenses, or compare a toll-free long way against a short congested cut-through. Prefer measured or typical average speeds for each corridor—posted limits overstate real progress when signals, hills, or construction slow traffic. On success the response echoes the six inputs after stable rounding, plus time_hours_a, fuel_needed_a, and fuel_cost_a for route A and the matching trio for route B. time_diff_hours and fuel_cost_diff are route B minus route A: a positive time_diff_hours means B takes longer; a positive fuel_cost_diff means B costs more in fuel. faster_route and cheaper_route are each the string a, b, or tie when times or costs match after rounding. This endpoint does not model elevation, weather, live congestion, or rest stops; it is a transparent arithmetic comparison, not a routing engine. Currency is whatever unit you use for fuel_price. Missing required fields, non-finite values, and non-positive distance, speed, or economy all fail with invalid_input and are not charged after the engine rejects the request.

API usage, pricing, travel workflows, and practical limits

Call the free in-browser compare-two-routes time and cost calculator for vacation planning, classroom demos, and quick corridor choices without installing a spreadsheet. For multi-leg itineraries, compare segment pairs client-side so each fork stays auditable. Send a JSON body with distance_a, average_speed_a, distance_b, average_speed_b, fuel_economy, and fuel_price (or the documented aliases). Use the prepaid API when a travel portal, fleet dashboard, logistics tool, or commute app needs a stable contract under KIT balance at $0.002 per successful item; validation failures never consume balance. Pair this endpoint with a single-trip fuel cost estimator when you only need one path, or with a road-trip time calculator when breaks matter more than a second geometry. Authors shipping SDKs can map faster_route and cheaper_route into UI badges while showing both time and cost side by side—the same trade-off drivers weigh when a GPS offers two alternatives.