Automotive Calculators โ€” Engine, Fuel, Tires, EV & Loan Tools

55+ free automotive calculators covering engine performance, fuel economy, wheels & tires, electric vehicles, and vehicle financing. From estimating horsepower and quarter-mile times to comparing tire sizes and calculating loan payments โ€” instant, accurate results for every automotive need.

Calculator Categories

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Engine & Performance (10)

Horsepower, torque, displacement, compression ratio, carburetor CFM, quarter mile, gear ratio & more.

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Fuel Economy (9)

Gas mileage (MPG), fuel cost, fuel savings, cost per mile, MPG โ†” L/100km converter & more.

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Wheels & Tires (8)

Tire size calculator, tire comparison, speedometer error, wheel offset, bolt pattern & more.

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EV Calculators (22)

EV vs gas comparison, charging cost & time, range estimator, tax credit eligibility, battery degradation & more.

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Vehicle Loan Calculators (7)

Auto loan, car lease, lease vs buy, motorcycle, boat, RV, and ATV loan payment calculators.

๐Ÿ”ง Engine & Performance Calculators

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Engine Horsepower Calculator

Calculate engine horsepower using RPM & torque, quarter-mile elapsed time, or trap speed methods. Supports HP, kW, and PS conversions.

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Engine Torque Calculator

Calculate engine torque from horsepower and RPM. Convert between lb-ft, Nm, and kg-m. See the torque curve relationship.

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Engine Displacement Calculator

Calculate engine displacement (CID/cc/L) from bore, stroke, and number of cylinders. Compare common engine configurations.

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Engine Compression Ratio Calculator

Calculate engine compression ratio from swept volume and clearance volume. Understand the impact on power and fuel octane requirements.

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Carburetor CFM Calculator

Calculate the correct carburetor size in CFM for your engine using displacement, RPM, and volumetric efficiency.

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0โ€“60 & Quarter Mile Calculator

Estimate quarter-mile elapsed time and trap speed from vehicle weight and horsepower. Calculate 0-60 mph time.

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Horsepower-to-Weight Ratio Calculator

Calculate power-to-weight ratio in HP/ton, lb/HP, and HP/liter. Compare your vehicle's performance potential against common benchmarks.

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Gear Ratio Calculator

Calculate overall gear ratio, RPM at speed, and speed at RPM from transmission gear, differential ratio, and tire size.

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Top Speed Estimator

Estimate a vehicle's theoretical top speed from horsepower, weight, drag coefficient, and frontal area.

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Dyno Correction Factor Calculator

Calculate SAE J1349, DIN 70020, and STD dyno correction factors from temperature, barometric pressure, and humidity.

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โ›ฝ Fuel Economy Calculators

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Gas Mileage Calculator

Calculate your vehicle's gas mileage (MPG) from distance traveled and fuel used. See cost per mile and metric equivalents.

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Fuel Cost Calculator

Calculate the fuel cost for any trip distance based on your vehicle's MPG and current gas price. Compare regular, mid-grade, and premium.

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Fuel Savings Calculator

Compare annual fuel costs between two vehicles. See how much you'd save by switching to a more fuel-efficient car.

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Cost Per Mile Calculator

Calculate the true all-in cost per mile including fuel, insurance, maintenance, depreciation, and financing.

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Fuel Injector Flow Rate Calculator

Calculate required fuel injector flow rate (lb/hr or cc/min) based on target horsepower, BSFC, number of injectors, and duty cycle.

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Fuel Tank Range Calculator

Calculate how far you can drive on a full tank or remaining fuel based on your vehicle's MPG and tank size.

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Annual Fuel Cost Calculator

Calculate your total annual fuel expenditure based on yearly miles driven, vehicle MPG, and local fuel price.

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MPG Improvement Savings Calculator

Calculate how much money you save by improving your vehicle's fuel economy from one MPG to another over a year.

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MPG to L/100km Converter

Convert between MPG (US), MPG (Imperial), km/L, and L/100km. Bidirectional fuel economy unit conversion with instant results.

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๐Ÿ›ž Wheels & Tires Calculators

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Tire Size Calculator

Decode any tire size (P-metric, LT-metric, flotation) into actual dimensions โ€” diameter, width, sidewall height, circumference, and revolutions per mile.

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Tire Size Comparison Calculator

Compare two tire sizes side by side โ€” diameter difference, width difference, speedometer error, and fitment compatibility.

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Tire Size Conversion Calculator

Convert tire sizes between P-metric (225/55R17), inches (28ร—10.50R15), and metric (750-16) formats.

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Speedometer Error Calculator

Calculate speedometer error caused by changing tire sizes. See your actual speed vs. displayed speed at any indicated speed.

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Speedometer Gear Calculator

Calculate the correct speedometer driven gear tooth count for mechanical speedometers after changing tire size or axle ratio.

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Wheel Offset Calculator

Calculate wheel offset (ET), backspacing, and track width change when switching to different wheels. Ensure safe fender clearance.

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Tire Pressure Adjustment Calculator

Calculate the correct tire pressure adjustment for temperature changes, load variations, and altitude. PSI and bar units supported.

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Bolt Pattern / PCD Calculator

Calculate Pitch Circle Diameter (PCD) from number of bolts and measurement between them. Find compatible wheel bolt patterns.

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๐Ÿ’ก Why Use Our Automotive Calculators?

Whether you're building a high-performance engine, shopping for the right tires, planning a road trip on a budget, or financing your next vehicle โ€” these automotive calculators give you the precise numbers you need. Every tool provides instant results with both US and metric units displayed inline, so you never have to convert manually.

Our engine calculators use industry-standard formulas (SAE J1349, Roger Huntington's ยผ-mile method) and include preset data for popular engines. Fuel economy tools compare costs across vehicles and project multi-year savings. Tire calculators decode P-metric notation, flag speedometer errors, and verify fitment safety โ€” all in real time as you type.

Start with the Engine Horsepower Calculator if you're building or tuning, the Gas Mileage Calculator if you're tracking fuel efficiency, or the Tire Size Comparison Calculator if you're upgrading wheels.

Automotive Calculator FAQ

Explore Other Categories

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Loan Calculators

EMI, eligibility & repayment planning tools

44 Calculators โ†’
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Investment Calculators

SIP, FD, mutual fund & compounding tools

17 Calculators โ†’
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Tax Calculators

Income tax, GST, HRA & TDS estimators

8 Calculators โ†’
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Utility Calculators

Age, percentage, unit & date converters

8 Calculators โ†’
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Conversion Calculators

mL, grams, ounces, cups & unit converters

54 Calculators โ†’
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Salary Calculators

CTC to in-hand, tax, gratuity & bonus tools

6 Calculators โ†’
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Business Calculators

Enterprise value, WACC, ROI & financial ratio tools

13 Calculators โ†’
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Time & Date Calculators

Time zones, date math, countdowns & scheduling tools

15 Calculators โ†’
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Construction Calculators

Concrete, roofing, flooring & building estimators

162 Calculators โ†’
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EV Calculators

Electric vehicle cost, charging, range & savings tools

22 Calculators โ†’
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Health Calculators

BMI, calories, body fat, TDEE & fitness tools

72 Calculators โ†’
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Math Calculators

Percentage, fractions, algebra, statistics & number tools

32 Calculators โ†’
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Pet Calculators

Dog age, cat age, chocolate toxicity & pet nutrition tools

5 Calculators โ†’
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Electrical Calculators

Amps, watts, volts, kVA & power conversion tools

39 Calculators โ†’
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Physics Calculators

Force, energy, velocity, acceleration & mechanics tools

26 Calculators โ†’
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Chemistry Calculators

Moles, molarity, pH, PPM & stoichiometry tools

20 Calculators โ†’
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Density Calculators

Density, metal weight, water weight & material tools

6 Calculators โ†’
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Vehicle Loan Calculators

Car, boat, motorcycle, RV & ATV loan payment tools

7 Calculators โ†’
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Cooking & Baking Calculators

Recipe scaling, ingredients matching & baking math

3 Calculators โ†’