Your bank beats a calculator
Gas calculators ask for your miles, your car's MPG and the local price, then estimate. If you already drive the car, you don't need an estimate: every fill-up is on a card statement. The problem is that it's spread across cards and mixed in with everything else.
An AI agent with read-only access to all your accounts can pull a year of fill-ups in one pass. With BankBridge connected to Claude, ChatGPT or another MCP client, it's one message.
Ask it
What did I spend on gas for my car each month over the last 12 months? Gas stations only, not the gas utility or rideshares. Give me the monthly totals, the number of fill-ups and the average per fill-up.
Ask in Claude · Ask in ChatGPT (with BankBridge connected)
The agent pulls a year of transactions with list_transactions and keeps the ones in the gas subcategory under transportation. That subcategory is what makes this work, for the reasons in the next sections.
The demo household's fuel year
From the BankBridge demo account (a made-up household with fictional data), October 24, 2025 to October 24, 2026, pulled 2026-10-24:
| Fill-ups | 24, about two a month |
|---|---|
| 12-month total | $1,362.20 |
| Per month | $113.52 on average, $97.88 to $121.82 |
| Per fill-up | $56.76 on average, $46.64 to $65.48 |
| Where | One Shell station, one Bank of America card |
The narrow monthly range is typical of a commute: the same trips, the same tank. A month well above the range usually means a road trip, a second driver or a price jump, and the agent can tell you which from the fill-up count and the per-fill-up average.
Two ways to get the wrong number
Searching for the word "gas". Station charges carry the brand, not the word. The demo's fill-ups read SHELL OIL #12345, and a text search for "gas" finds none of them. Meanwhile the household's natural gas utility bill, $981.25 for the year, sits in a utilities category whose name includes gas. Search by word and you can get zero, or the heating bill. The fuel subcategory avoids both.
Using the whole transportation category. A spending summary by category groups on the top-level category, and transportation holds more than fuel. In the demo year it's $2,504.14: the $1,362.20 in fill-ups plus $1,141.94 in rideshares. Ask for the gas subcategory, or the agent will hand you a number nearly twice as high.
Break down my transportation spending for the last 12 months by subcategory: fuel, rideshares, parking, tolls and anything else.
How it compares
The Bureau of Labor Statistics' Consumer Expenditure Survey puts average 2024 gasoline spending at $2,411 per household, about $201 a month (BLS, Consumer Expenditures in 2024, released December 19, 2025). That average includes households with two or three cars and long commutes, and households with none. The demo household, one car and a short commute, spends a bit over half of it.
Compare my monthly gas spending with the 2024 US household average of $201. How many fill-ups a month am I doing, and what's my average per fill-up?
Pay-at-the-pump holds
When you pay at the pump, the station often places a temporary hold before it knows the final amount. The pending charge you see can differ from what posts a day or two later. For monthly totals, ask for posted charges only, so a placeholder hold doesn't stand in for the real fill-up.
Using the number
- Budgeting. Use the 12-month average, not last month. Our guide on not projecting from one month explains why.
- Picking a card. If fuel is a big line, a card with a gas category bonus may pay. See picking a credit card from your real spending.
- Driving for work. If you drive for gig work or a side business, fuel totals help you check your mileage records. The IRS has its own rules for what you can deduct, so keep the mileage log your tax preparer asks for.
Want to see it before connecting anything? The demo account has a year of a made-up household’s transactions. Add it to your agent from the demo dashboard, then ask: “How much does this household spend on gas for the car each month, gas stations only?” (what’s in the demo)
On your own accounts, BankBridge is read-only and fetches live from your bank on every question. It costs $5 a month or $50 a year per connected bank.