Fuel Cost Calculator: Estimate Gas Costs for Any Trip

Need to know how much gas a trip will cost? Use this formula:

Fuel cost = miles driven ÷ MPG × price per gallon

This guide uses U.S. miles, miles per U.S. gallon (MPG), U.S. gallons, and U.S. dollars (USD). Convert kilometers or liters before using the formula. $3.40 per gallon is an illustrative assumption throughout this guide, not a national average for 2026. Use your local price and vehicle MPG.

Example: a 300-mile trip in a car that gets 30 MPG at $3.40/gallon costs:

300 ÷ 30 × $3.40 = $34.00

For a single trip, use the formula and lookup tables in this guide. WiseCalc's free Fuel Cost Calculator compares annual fuel costs for two vehicles. Enter miles per year, the local price in USD per U.S. gallon, two MPG values, and a comparison period in years. It shows annual fuel costs, average monthly costs, and totals for the selected years.

This guide shows the fuel-cost formula, quick lookup tables, and when fuel cost is different from true cost per mile.

How to Calculate Gas Cost for a Trip

Fuel cost per mile is a simple division problem:

Gas price per gallon ÷ MPG = fuel cost per mile

For a trip or annual estimate, use:

Miles driven ÷ MPG × gas price = estimated fuel cost

What inputs do you need?

• Distance - trip miles, commute miles, or total miles driven
• MPG / mileage - your vehicle's real-world fuel economy
• Fuel price per gallon - local regular, premium, or diesel price
• Optional annual miles - useful for yearly fuel budget estimates

Examples at $3.40 per gallon:

Gas Cost for a Trip

Trip fuel cost scales with distance, MPG, and price per gallon. At $3.40 per gallon, here are quick estimates for common drive lengths:

Quick Gas Cost Table

Use this table for a fast estimate at $3.40/gallon.

If your gas price or MPG is different, recalculate the trip formula above. For an annual two-vehicle comparison, use the fuel cost calculator with yearly mileage, fuel price, both MPG values, and comparison years.

A 300-mile trip in a 28 MPG vehicle at $3.40/gallon costs:

300 miles ÷ 28 MPG × $3.40 ≈ $36.43

Depending on exact MPG and rounding, the trip fuel budget is roughly $36-$37 before tolls, parking, lodging, or vehicle wear. True cost per mile is the next step when you also need to account for depreciation, insurance, maintenance, tires, and financing.

How to Calculate Annual Fuel Cost

Annual fuel cost uses the same formula:

Annual miles ÷ MPG × price per gallon = annual fuel cost

Example: if you drive 15,000 miles/year, get 28 MPG, and pay $3.40/gallon:

15,000 ÷ 28 × $3.40 ≈ $1,821/year

That is about $152/month for fuel. Annual and monthly results are independently rounded to whole dollars from the unrounded formula, with unchanged mileage, MPG, and price assumptions. If you are comparing cars, annual fuel cost matters more than one-trip cost because MPG differences compound every year.

Fuel Cost Per Mile by Vehicle Type

The biggest fuel-cost lever is efficiency. At the same gas price, a large SUV can cost more than twice as much per mile in fuel as a hybrid.

Assuming 15,000 miles per year and $3.40/gallon:

Fuel is only one part of the decision. A newer hybrid may save on gas but cost more upfront, while an older paid-off SUV may have higher fuel expense but lower depreciation. Compare purchase tradeoffs with the New vs. Used Car Calculator, then pressure-test the monthly payment with the Car Affordability Calculator.

The 5 Components of True Cost Per Mile

A broader vehicle budget includes fixed ownership costs and mileage-dependent operating costs. The component ranges and comparison table below are hypothetical planning scenarios, not national averages or AAA findings. Gas is visible because you pay for it regularly; depreciation, insurance, tires, and interest also affect a budget. Allocating a fixed annual cost across miles does not make that cost disappear when you drive less.

1. Fuel (~8-19¢ per mile)

At the illustrative $3.40/gallon assumption:

• Hybrid or efficient compact (45 MPG): ~8¢/mile
• Economy car (35 MPG): ~10¢/mile
• Midsize sedan (28 MPG): ~12¢/mile
• SUV/truck (20 MPG): ~17¢/mile

This is the cost most people track - and the easiest to reduce.

2. Depreciation (~10-45¢+ per mile)

Depreciation is usually the biggest hidden cost, especially for new vehicles. A $40,000 car that loses $6,000 in value over a year costs 40¢ per mile in depreciation if driven 15,000 miles. If driven only 8,000 miles, that same $6,000 loss becomes 75¢ per mile.

This is why per-mile costs vary so much. High-mileage drivers spread depreciation over more miles, while low-mileage owners often pay a surprisingly high cost per mile even when fuel spending looks low.

Depreciation is also why used cars can be cheaper per mile than new ones. A 3-year-old certified pre-owned vehicle may have already absorbed the steepest part of the value drop. Compare your options with the New vs. Used Car Calculator.

3. Insurance (~8-20¢ per mile)

Insurance is a fixed cost that becomes a per-mile cost when you divide it by mileage. For example:

• $1,500/year ÷ 15,000 miles = 10¢ per mile
• $2,100/year ÷ 15,000 miles = 14¢ per mile
• $2,400/year ÷ 10,000 miles = 24¢ per mile

Your rate depends on location, coverage, vehicle value, driving history, credit profile in many states, and deductible choices. Drive fewer miles and your per-mile insurance cost rises even if the premium stays flat.

4. Maintenance and Tires (~6-12¢ per mile)

Maintenance includes oil changes, filters, brakes, tires, batteries, alignment, inspections, and unexpected repairs. As an illustration, $1,200 of annual maintenance and tire spending divided by 15,000 miles is 8¢ per mile. Use your own records and expected repairs instead of treating this example as an average.

Skipping maintenance can make the short-term number look better while increasing long-term repair risk. A cheap mile today can become an expensive mile later.

5. Financing (~3-10¢ per mile)

If you financed your car, interest is a real ownership cost. A $30,000 loan at 6.5% over 60 months can generate roughly $5,200 in total interest. Spread across 75,000 miles, that is about 7¢ per mile.

Use the Auto Loan Calculator to see exactly what interest you'll pay, or the Car Affordability Calculator to set a budget that keeps your total per-mile cost reasonable. Russian-language readers can also run the same payment scenario in the Russian auto loan calculator. Our auto loan guide explains how loan term length affects your total interest paid - a longer loan lowers monthly payments but raises your per-mile financing cost.

Real-World Examples: What Driving Actually Costs

Daily Commuter

A 30-mile round-trip commute over 250 workdays totals 7,500 miles. At an illustrative allocated cost of 81¢ per mile, that is $24.30 per workday or $6,075 per year. At 28 MPG and $3.40/gallon, its fuel alone is about $911/year. The broader figure allocates ownership expenses; it is not a promise of cash you would save by eliminating those miles.

Weekend Road Trip

A 300-mile weekend trip in a 28 MPG sedan costs $36.43 in fuel at the illustrative $3.40/gallon price. A separate hypothetical total-cost allocation of 70-80¢ per mile gives $210-$240 before food, lodging, tolls, and parking. That broader amount already includes fuel: do not add the fuel receipt again. It also includes ownership allocations rather than only additional trip cash spending.

Business Mileage

Separate fuel budgeting from business-mileage tax rules. An IRS tax method is not automatic employer reimbursement. Record the purpose, date, and mileage of business travel, and compare any reimbursement agreement with your own costs rather than treating a tax rate as a gasoline price.

Cost Per Mile Comparison Table

These hypothetical ranges combine fuel, depreciation, insurance, maintenance, and financing. They are not measured national averages or quotes. Your numbers depend on your own expenses, vehicle age, annual mileage, and loan terms.

Tips by Vehicle Type

Economy Cars and Hybrids

Fuel-efficient cars shine for commuters and high-mileage drivers. Keep tires properly inflated, avoid aggressive acceleration, and compare insurance quotes annually so savings are not erased by premiums.

SUVs and Pickups

For SUVs and pickups, fuel is only part of the premium. Tires, brakes, insurance, and depreciation can all run higher. If you need towing or cargo capacity, budget for the real cost. If you do not, compare the savings from downsizing before your next purchase.

Older Paid-Off Cars

A paid-off car can be the cheapest vehicle per mile when it is reliable. The key is separating routine maintenance from repeated major repairs. If repair costs start averaging hundreds per month, compare keeping it with buying used before the next expensive fix.

New Financed Cars

New financed cars often feel affordable because the monthly payment is visible and depreciation is not. Shorter loan terms, larger down payments, and avoiding unnecessary upgrades can reduce the true per-mile cost more than small MPG differences.

How to Reduce Your Cost Per Mile

Drive a higher-MPG vehicle. Moving from 20 MPG to 35 MPG at the illustrative $3.40/gallon price reduces fuel cost by about 7.3¢/mile, or $1,093/year at 15,000 miles. Over five years with unchanged assumptions, that is about $5,464. These rounded results use the unrounded formula and exclude any difference in purchase price.

Buy used, especially 2-3 years old. Skip the steepest depreciation curve. A certified pre-owned vehicle may have the same MPG as a new one, at a lower purchase price and lower monthly payment.

Shop insurance annually. The same driver and vehicle can receive very different quotes. A $300/year premium reduction saves 2¢ per mile at 15,000 miles.

Maintain the vehicle before repairs compound. Tires, brakes, fluids, filters, and alignments are cheaper than preventable failures. Follow the owner's manual and keep service records for resale value.

Drive fewer miles intentionally. Consolidate errands. Use the Monthly Budget Calculator to quantify how your commuting costs fit - and whether remote work days or a carpool would meaningfully impact your budget.

When Cost Per Mile Matters Most

Choosing Between Two Cars

If Car A costs $30,000 and gets 35 MPG while Car B costs $40,000 and gets 25 MPG, compare total per-mile cost - not just sticker price, fuel economy, or monthly payment. Run both through the Car Affordability Calculator and compare over 5 years. Our guide on how much car you can afford walks through the 20/4/10 rule for setting a realistic total vehicle budget.

Deciding on a Commute

A 30-mile round-trip commute over 250 workdays is 7,500 miles. At the illustrative 81¢/mile allocation, that is $6,075/year; an extra $400/month in rent is $4,800/year. This comparison alone does not establish cash savings from moving. Estimate the remaining commute, fuel and other mileage-dependent expenses, and any ownership costs that would actually change. Fixed insurance, financing, and some depreciation may remain.

Road Trips vs. Flying

For a 600-mile round trip, an illustrative 81¢/mile allocation is $486 before lodging or parking. Compare that with your actual flight quote; a hypothetical $150-$300 ticket is a comparison input, not a current airfare claim. Separate additional trip cash expenses from allocated ownership costs, and include any extra hotel night or airport transport.

Reimbursement and Taxes

Verified 2026-10-06: the IRS standard-mileage table lists eligible 2026 business mileage at 72.5¢ per mile for January 1-June 30 and 76¢ for July 1-December 31. This is an optional tax method based on fixed and variable vehicle costs, not a gasoline price, your actual full cost, or guaranteed employer reimbursement. Use and recordkeeping requirements apply; Announcement 2026-11 also specifies date conditions for employee allowances.

Charitable mileage has a separate statutory 14¢ per mile rate, not the business rate's full-cost rationale. The initial 2026 IRS announcement explains the distinction; it alone does not reflect the later July business-rate change.

Frequently Asked Questions

How do I calculate gas cost for a trip?

Divide trip miles by your vehicle's MPG, then multiply by gas price per gallon. Example: 300 miles ÷ 30 MPG × $3.40 = $34.00.

How much gas money do I need for 100 miles?

At $3.40/gallon, 100 miles costs about $17.00 at 20 MPG, $13.60 at 25 MPG, $11.33 at 30 MPG, and $9.71 at 35 MPG.

How do I calculate annual fuel cost?

Use: annual miles ÷ MPG × gas price. If you drive 15,000 miles/year at 28 MPG with gas at $3.40/gallon, annual fuel cost is about $1,821.

Is MPG or gas price more important?

Both enter the same formula: compare the actual MPG and price changes. Going from 20 MPG to 30 MPG reduces modeled fuel cost by $850/year at 15,000 miles and the illustrative $3.40/gallon price, with other assumptions unchanged.

Is fuel cost the same as cost per mile?

No. Fuel cost per mile only counts gasoline. True cost per mile also includes depreciation, insurance, maintenance, tires, and loan interest.

What costs beyond gas should I include in cost per mile?

Include depreciation, insurance, maintenance and tires, and loan interest if financed. For new vehicles, depreciation is often the largest single cost. For older vehicles, repairs and maintenance may matter more.

Is it cheaper to drive or take public transit?

Compare your round-trip miles, workdays, local transit fares, parking, and remaining driving. Count fuel and other expenses that would actually change; allocated fixed insurance or financing may remain. Neither option is universally cheaper, and transit availability also matters.

How can I reduce my cost per mile?

The biggest levers are buying a reliable used or fuel-efficient vehicle, avoiding oversized loans, shopping insurance annually, maintaining the vehicle on schedule, and reducing unnecessary miles.

Calculate Your Exact Fuel Cost

Planning a drive? Estimate its fuel cost with the trip formula and table above, then add other trip expenses separately. For a longer-term comparison, WiseCalc's fuel cost calculator models two vehicles using the same annual mileage and fuel price.

Enter annual U.S. miles, USD per U.S. gallon, each vehicle's MPG, and comparison years in the annual fuel comparison. Its monthly figures are annual costs divided by twelve; its multi-year totals keep those annual assumptions constant. Ownership expenses are separate from the calculator's fuel costs.

Explore the full Auto Calculator Hub for loan payments, lease comparisons, refinancing, and more - everything you need to make confident decisions about your vehicle budget.

Fuel prices and ownership ranges are illustrative U.S.-unit scenarios, not national averages or promises of your expenses. The secondary tax note was verified against the linked IRS primary sources as of 2026-10-06.