Gas Mileage Calculator - MPG, Fuel Efficiency & Mileage Tracker

Calculate gas mileage, track MPG & fuel efficiency. Monitor km/L, L/100km, compare vehicles & improve fuel economy. Free mileage calculator with detailed tracking and unit conversion.

Global Settings

Distance Unit

Fuel Unit

Fuel Price per Gallon

Quick Info

1 gallon = 3.785 L

1 mile = 1.609 km

Basic Mileage Calculator

Calculate your vehicle's fuel efficiency

Distance Traveled (miles)

Fuel Used (gallons)

📊 Fuel Efficiency Guide

Excellent

40+ MPG

Hybrid/Electric level

Good

30-40 MPG

Efficient vehicles

Average

20-30 MPG

Standard cars

Poor

15-20 MPG

SUVs/Trucks

Very Poor

<15 MPG

Heavy vehicles

💡 Tips to Improve Gas Mileage

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Maintain Speed

55-65 mph is optimal

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Tire Pressure

Check monthly

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Reduce Weight

Remove excess cargo

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Regular Service

Follow maintenance schedule

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AC Usage

Use sparingly

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Plan Routes

Avoid traffic & hills

How to Use the Gas Mileage Calculator

Basic Mileage Calculation

1. Select your preferred unit (km/L, MPG, or L/100km)
2. Choose distance unit (kilometers or miles)
3. Enter distance driven since last fill-up
4. Input fuel added at fill-up (liters or gallons)
5. View instant mileage calculation
6. Track your fuel efficiency over time

Mileage Tracking Mode

1. Record odometer reading at each fill-up
2. Note fuel quantity added
3. Calculate mileage for each fill-up
4. View average mileage over multiple fill-ups
5. Compare current vs historical performance
6. Identify trends and efficiency changes

Unit Conversion

1. Enter mileage in any unit (km/L, MPG, L/100km)
2. View automatic conversion to all other units
3. Compare efficiency across different standards
4. Understand global fuel economy ratings
5. Use for vehicle comparison shopping

Efficiency Monitoring

1. Track mileage at every fill-up
2. Calculate monthly average efficiency
3. Compare city vs highway mileage
4. Monitor seasonal variations
5. Identify maintenance needs from drops

Pro Tip: For most accurate results, always fill your tank to the same level (full) and calculate mileage over multiple fill-ups. Single fill-up calculations can vary due to pump differences and tank filling variations.

Understanding Gas Mileage & Fuel Efficiency

What is Gas Mileage?

Gas mileage (fuel efficiency) measures how far your vehicle travels per unit of fuel consumed. It's the most important metric for understanding vehicle fuel economy and operating costs. Higher mileage means better efficiency and lower fuel costs.

Mileage Calculation Formula

Basic Formula: Mileage = Distance Driven ÷ Fuel Consumed
km/L: Kilometers ÷ Liters (higher is better)
MPG: Miles ÷ Gallons (higher is better)
L/100km: (Liters ÷ Kilometers) × 100 (lower is better)

km/L (Kilometers per Liter)

Common in India, Asia, Africa

Example: 15 km/L means 15 km traveled per liter

Good: 15-20 km/L | Excellent: 20+ km/L

MPG (Miles per Gallon)

Used in USA, UK

Example: 35 MPG means 35 miles per gallon

Good: 30-40 MPG | Excellent: 40+ MPG

L/100km (Liters per 100km)

European standard

Example: 6 L/100km means 6 liters per 100 km

Good: 5-7 L/100km | Excellent: <5 L/100km

Factors Affecting Gas Mileage

Driving Style: Aggressive driving reduces mileage by 15-30%. Smooth acceleration and steady speed improve efficiency.
Vehicle Maintenance: Proper tire pressure, clean air filter, and regular service maintain optimal mileage.
Speed: Optimal efficiency at 50-80 km/h. Higher speeds increase aerodynamic drag exponentially.
Load & Weight: Extra 50 kg reduces efficiency by 1-2%. Remove unnecessary items from vehicle.
Weather Conditions: Cold weather reduces mileage by 15-20%. AC usage decreases efficiency by 10-20%.
Traffic Conditions: Stop-and-go traffic significantly reduces mileage compared to steady highway driving.
Terrain: Hills and mountains increase fuel consumption. Flat roads provide better mileage.
Vehicle Condition: Engine problems, worn spark plugs, and misalignment reduce efficiency.

Mileage Tracking & Monitoring

Why Track Gas Mileage?

Regular mileage tracking helps identify vehicle problems early, optimize fuel costs, and maintain peak efficiency. A sudden drop in mileage often indicates maintenance needs before major issues develop.

Benefits of Tracking

✓ Early detection of vehicle problems
✓ Optimize fuel costs and budget
✓ Verify manufacturer claims
✓ Compare driving conditions impact
✓ Track maintenance effectiveness
✓ Make informed vehicle decisions

Tracking Best Practices

✓ Fill tank completely each time
✓ Record odometer at every fill-up
✓ Note fuel quantity precisely
✓ Track date and location
✓ Calculate average over 3-4 fill-ups
✓ Compare seasonal variations

Step-by-Step Tracking Method

Step 1: Fill your tank completely until pump automatically stops
Step 2: Record exact odometer reading (e.g., 45,230 km)
Step 3: Drive normally until next fill-up (don't change driving habits)
Step 4: Fill tank completely again at next fuel stop
Step 5: Record new odometer reading (e.g., 45,680 km)
Step 6: Note exact fuel quantity added (e.g., 30 liters)
Step 7: Calculate: (45,680 - 45,230) ÷ 30 = 15 km/L
Step 8: Repeat process for accurate average over time

Important: Single fill-up calculations can vary by ±10% due to pump differences and tank filling variations. Always calculate average over 3-4 fill-ups for reliable data.

How to Improve Gas Mileage

Driving Techniques for Better Mileage

Acceleration & Speed

✓ Accelerate gradually and smoothly
✓ Maintain steady speed (50-80 km/h optimal)
✓ Use cruise control on highways
✓ Anticipate traffic to avoid sudden braking
✓ Coast to red lights instead of braking hard
✓ Avoid excessive idling (turn off after 30 sec)

Smart Driving Habits

✓ Plan routes to avoid traffic congestion
✓ Combine multiple errands into one trip
✓ Avoid rush hour when possible
✓ Use GPS for shortest efficient routes
✓ Remove roof racks when not in use
✓ Close windows at highway speeds

Vehicle Maintenance for Optimal Mileage

Tire Pressure: Check monthly. Proper inflation improves mileage by 3-5%. Under-inflated tires increase rolling resistance.
Engine Oil: Use manufacturer-recommended grade. Synthetic oil can improve efficiency by 1-2%.
Air Filter: Replace every 15,000-20,000 km. Clogged filter reduces mileage by up to 10%.
Spark Plugs: Replace as per schedule. Worn plugs cause incomplete combustion and poor mileage.
Wheel Alignment: Misalignment increases rolling resistance and tire wear, reducing efficiency.
Regular Service: Follow manufacturer's service schedule. Well-maintained engines run more efficiently.
Fuel System: Clean fuel injectors periodically. Dirty injectors reduce combustion efficiency.
Oxygen Sensor: Faulty sensor can reduce mileage by 40%. Replace if check engine light appears.

Additional Fuel-Saving Strategies

Weight Reduction

• Remove unnecessary items
• Empty trunk regularly
• Remove roof racks
• Don't carry extra fuel

Climate Control

• Use AC wisely (10-20% impact)
• Park in shade
• Use recirculation mode
• Windows down at low speeds

Fuel Quality

• Use recommended octane
• Fill at reputable stations
• Avoid overfilling tank
• Tighten gas cap properly

Vehicle Mileage Comparison

Comparing Vehicle Efficiency

When buying a vehicle, mileage comparison is crucial for long-term cost analysis. A vehicle with 20% better mileage can save thousands annually. Use our calculator to compare actual mileage between vehicles and calculate break-even points.

Mileage by Vehicle Type

Passenger Vehicles

Small Cars: 18-25 km/L (42-59 MPG)
Sedans: 15-20 km/L (35-47 MPG)
SUVs: 10-15 km/L (24-35 MPG)
Luxury Cars: 8-12 km/L (19-28 MPG)
Sports Cars: 6-10 km/L (14-24 MPG)

Alternative Fuel Vehicles

Hybrids: 20-30 km/L (47-70 MPG)
Plug-in Hybrids: 25-35 km/L (59-82 MPG)
Diesel: 18-25 km/L (42-59 MPG)
CNG: 20-28 km/kg equivalent
Electric: 5-7 km/kWh (MPGe: 100-130)

Real-World Comparison Example

Sedan vs Hybrid Comparison

Regular Sedan

• Mileage: 15 km/L
• Annual Distance: 15,000 km
• Fuel Needed: 1,000 liters
• Fuel Cost: ₹100,000/year
• Purchase Price: ₹10,00,000

Hybrid Sedan

• Mileage: 25 km/L
• Annual Distance: 15,000 km
• Fuel Needed: 600 liters
• Fuel Cost: ₹60,000/year
• Purchase Price: ₹14,00,000

Annual Savings: ₹40,000 | Break-even: 10 years |5-year Savings: ₹2,00,000 - ₹4,00,000 = -₹2,00,000 (still recovering cost)

Troubleshooting Poor Gas Mileage

Common Causes of Decreased Mileage

Sudden Drop (10-20%)

Indicates immediate problem requiring attention:

• Check engine light on - scan for codes
• Oxygen sensor failure (40% drop possible)
• Dragging brakes - feel for hot wheels
• Tire pressure very low - check immediately
• Fuel leak - check for smell or puddles

Gradual Decline (5-10%)

Indicates maintenance needs:

• Dirty air filter - replace every 15,000 km
• Worn spark plugs - replace per schedule
• Old engine oil - change every 5,000-10,000 km
• Wheel misalignment - get alignment check
• Dirty fuel injectors - use cleaner or service

Seasonal Variation (10-15%)

Normal variations due to conditions:

• Winter: Cold starts, thicker oil, battery load
• Summer: AC usage increases consumption
• Rain/Snow: Increased rolling resistance
• Wind: Headwinds reduce efficiency
• Traffic: More congestion in certain seasons

Diagnostic Checklist

Check tire pressure: Inflate to recommended PSI (usually 32-35 PSI)
Inspect air filter: Replace if dirty or clogged
Verify fuel cap: Ensure tight seal (loose cap causes evaporation)
Review driving habits: Track aggressive driving instances
Check for warning lights: Scan for diagnostic codes
Inspect brakes: Ensure no dragging or sticking
Review recent changes: New tires, roof rack, extra weight?
Compare conditions: City vs highway, weather changes

Frequently Asked Questions (FAQs)

How do I calculate gas mileage?

To calculate gas mileage: (1) Fill your tank completely, (2) Note the odometer reading, (3) Drive normally until next fill-up, (4) Fill tank again and note liters/gallons added, (5) Note new odometer reading, (6) Calculate: Mileage = Distance Driven ÷ Fuel Added. Example: 450 km driven, 30 liters added = 15 km/L. For MPG: miles driven ÷ gallons added.

What is good gas mileage for a car?

Good gas mileage varies by vehicle type: Small cars: 18-25 km/L (42-59 MPG),Sedans: 15-20 km/L (35-47 MPG), SUVs: 10-15 km/L (24-35 MPG),Trucks: 8-12 km/L (19-28 MPG), Hybrids: 20-30 km/L (47-70 MPG). In L/100km: lower is better - 4-6 L/100km is excellent, 6-8 is good, 8-10 is average.

How to improve gas mileage?

Improve mileage by: Driving habits - smooth acceleration, steady speed (50-80 km/h), avoid idling, anticipate traffic. Maintenance - proper tire pressure (+3-5%), regular oil changes, clean air filter, tune-ups. Weight reduction - remove unnecessary items, empty roof racks. Aerodynamics - close windows at high speed, remove roof racks.Smart planning - combine trips, avoid traffic, use GPS for shortest routes. These strategies can improve mileage by 20-40%.

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