Automotive Calculators

Compute miles per gallon from distance and gallons used. Also returns L/100km.

Estimate fuel cost from trip distance, fuel economy, and price per unit. Toggle miles/km, MPG / km per L / L per 100 km, and $/gal vs $/L.

Estimate how far you can drive on a full tank from MPG and tank capacity.

speed = distance / time. Pick units and read average speed in mph or km/h.

distance = speed × time. Useful for "if I drive X mph for Y hours, how far?" questions.

How long will a road trip take? Distance / speed plus breaks and fuel stops.

Given remaining distance and speed, when will you arrive?

a = (v_final − v_initial) / time. Useful for 0-60 times and physics problems.

Auto loan payment via amortization. Principal, APR, term → monthly + total interest.

Compare 36-mo lease total cost vs. 5-yr purchase + resale. Same out-of-pocket cash basis.

Max car price = (monthly budget × loan factor) using 20/4/10 rule and DTI cap.

Straight-line or declining-balance depreciation. Most cars lose 15-25% year 1, 50%+ by year 5.

Purchase + insurance + fuel + maintenance + depreciation over N years.

Miles since last × interval-miles → next due date and miles. By oil type.

Fluid + labor cost. Recommended every 2 years or 30,000 miles.

Fluid + filter + labor cost for ATF service. Every 30-60k miles depending on type.

Coolant + thermostat (optional) + labor. Every 60-100k miles or 5 years.

Towing = GCWR − vehicle weight − passengers − payload. Stay 80% of max for safety.

RPM = (MPH × 336 × ratio) / tire-diameter. Find RPM at given speed for any axle ratio.

P-metric (215/65R16) → overall diameter, revolutions/mile, sidewall height.

Tire PSI changes ~1 psi per 10°F. Adjust for outdoor temp delta from setting temp.

cc ↔ liters ↔ cubic inches. 1 L = 1000 cc; 1 cu in = 16.387 cc.

T (lb-ft) = 5252 × HP / RPM. The fundamental engine equation.

HP = T × RPM / 5252. Converts engine torque to power at given RPM.

Better MPG → annual fuel savings. (1 − base/improved) × annual gas cost.

Calculate miles per gallon from miles driven and gallons used, average several trips at once, and convert to L/100 km and km/L.

Estimate the fuel cost of a trip from distance, your vehicle MPG, and the price of gas — with multi-leg trips and a round-trip option.

See whether refinancing your car loan pays off: compare payments, monthly savings, and the month you recoup any refinancing fees.

Estimate a monthly car lease payment from the vehicle price, residual value, money factor (or APR), and lease term.