GasCap™

Know before
you go.

Calculate fuel & cost before you pull up to the pump.

⛽Real-time prices
✓Works offline
💰Free · Pro $4.99/mo

Fill up in the morning — fuel is denser when it's cool, so you get slightly more per gallon.

Know exactly how much gas you need — before you pull up.

With gas prices near record highs, know your exact fill-up cost before you swipe your card. No guessing. No overpaying.

⛽Live local prices🚗Rental car mode📊MPG tracking🤖AI advisor🏎️Vehicle Garage📋Fill-up History
🎁

Sign up today — first 30 days of Pro FREE

$4.99/mo after trial · No credit card · Cancel anytime

Free forever · Pro $4.99/mo · Fleet $19.99/mo  · See all plans ↓

Partnering with local businesses

Fuel & Convenience
Quick Lube
Tires & Wheels
Auto Detailing
Auto Repair
C-Store & Fuel
Pre-Owned Vehicles
Fuel & Convenience
Fuel & Convenience
Quick Lube
Tires & Wheels
Auto Detailing
Auto Repair
C-Store & Fuel
Pre-Owned Vehicles
Fuel & Convenience
⛽

Fill-Up Calculator

Set your tank, current level, and target fill — we'll tell you exactly what to pump and what it costs.

How to use

1Pick a vehicle
2Set fuel level

Current Fuel Level

1/64 tank step

Drag the handle · or tap anywhere on the arc

📷

Sign in to use AI gauge scan and auto-detect your fuel level from a photo.

3Choose a goal

Fill Up To

4Get the answer

Gas Price per Gallon

$
💾

Save your calculations

Free account — no credit card ever.

Sign up free
⚡

Tools & Insights

🤖

AI Fuel Advisor

Get personalized fuel-saving tips, trip estimates, and smart driving advice.

Stop guessing at the pump

GasCap™ solves the three most frustrating gas station moments.

💳

Wondering if you have enough cash to fill up

✓ Know the exact cost before you swipe your card

🚗

Returning a rental car on empty — $12/gallon fees

✓ Calculate exactly how many gallons to buy first

📊

No idea what you're spending on gas each month

✓ MPG trends and monthly spend tracked automatically

⚡

Everything you need to stop overpaying

⛽✓ Free

Fuel calculator

Enter your tank level, pick a target fill, and get the exact gallon count and cost — in seconds.

📍🔑 Free acct

Live gas prices

Real-time local prices from the U.S. EIA — auto-detected by location. Free with an account.

📡✓ Free

Works offline

Install it like an app. No signal? The calculator always works with your saved data.

📊⭐ Pro

MPG & spend tracking

Log every fill-up. See your efficiency trends, monthly spend, and fuel cost per mile.

🤖⭐ Pro

AI fuel advisor

Ask anything — best fill strategy, octane grade, or how to improve your MPG.

📄⭐ Pro

PDF & CSV export

Export your fill-up history and fuel reports for personal finance or fleet records.

Renting a car? Never overpay at drop-off.

Rental companies charge up to $12/gal if you return empty. GasCap™ Rental Car Return Mode tells you exactly how many gallons to buy — and shows your exact savings vs. letting them fill it.

Toggle "🚗 Rental Car Return?" in the calculator above.

👤

Who uses GasCap™

🚘

Daily Drivers

Know your fill-up cost every time. Budget your gas spend to the dollar.

✈️

Frequent Travelers

Use Rental Car Return Mode to skip the $12/gal refueling trap every trip.

🗺️

Road Trippers

Plan your fuel budget stop by stop. Know costs before you leave the driveway.

🚛

Fleet Managers

Track fuel costs across your entire fleet. Export reports. Control spending.

Why drivers trust GasCap™
Works offline — no signal needed
We never sell your data
Powered by U.S. EIA official data
No credit card to start — ever

Free

Forever — no catch

5.0★

Average rating

<2s

Typical calculation

🎁 Recent Giveaway Winners

Matt B.

April 2026

$25 Visa Prepaid Card

A new winner is drawn every month. Create a free account to enter automatically.

❓

Frequently Asked Questions

Plans & Pricing

Start free. Upgrade when you're ready. No surprises.

Free

No CC Ever
$0/forever

Full calculator · gas prices · offline PWA · no catch

  • 1 saved vehicle
  • Target Fill calculator
  • By Budget calculator
  • EPA vehicle database search
  • Live gas price lookup
  • Badge achievements
  • Works offline (PWA)
⭐ Most Popular

Pro

Individuals & Couples
$4.99/mo

Billed monthly · cancel anytime

  • Everything in Free
  • Up to 3 saved vehicles
  • Manual entry + auto spec lookup
  • Engine type & tank size auto-detected
  • MPG trending chart
  • Fuel cost PDF export
  • Monthly fuel budget tracker
  • SMS fill-up reminders (coming soon)
  • Referral rewards
  • Priority support

Fleet

Household & Business
$19.99/mo

Billed monthly · cancel anytime

  • Everything in Pro
  • Unlimited vehicles
  • Household & multi-vehicle use
  • Shared fleet garage
  • Fleet cost dashboard
  • Annual tax report (PDF)
  • Bulk vehicle import
  • Per-vehicle spending breakdown
  • CSV export for accounting
  • Referral rewards
  • Multi-driver sub-accounts (coming soon)
  • Dedicated support

30-Day Satisfaction Guarantee

If GasCap Pro doesn't help you save more than $4.99 in your first month, contact us and we'll refund your first payment — no questions asked.

🔒 We never sell your data💳 Secured by Stripe✓ Cancel anytime
⭐30 days of Pro free — no credit card ever

Know before
you pull up.

Start with 30 free days of Pro — then $4.99/mo, cancel anytime. Save your vehicles, track your MPG, and stop over-paying at the pump.

Start free — 30 days Pro included →

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