Planning tool · Tank capacity
Fuel tank sizing calculator
Turn fuel usage, days of supply, reserve, and expected growth into a practical planning capacity before you start shopping for a tank.
Planning result
Normalized use
0 gal/day
Base supply
0 gal
Planning band
—
This is a planning estimate, not a code-required tank size or a guarantee that a specific nominal tank capacity is available. Final capacity should account for delivery practices, usable operating volume, site constraints, product availability, and the governing AHJ/regulatory requirements.
What the calculator is doing
The tool converts your usage to an average daily rate, multiplies it by the desired days of supply, then applies the reserve and growth percentages you selected. The result is intentionally called a planning capacity. It is a starting point for sourcing and site planning, not a substitute for the final tank specification.
Inputs that can change the final tank
- How many gallons your supplier can or wants to deliver at a time
- How much operational reserve you need during peak periods
- Available site footprint and delivery-truck access
- Permanent versus relocatable use
- Pump flow, hose reach, metering, fuel management, and monitoring
- SPCC, fire-code, state/provincial, and local AHJ requirements
Methodology & assumptions
What this calculator answers—and what it does not.
The calculator normalizes the fuel-use input to an average daily rate, multiplies that rate by the desired days of supply, then applies the reserve and growth percentages you select. The output is a planning capacity: a useful starting point for sourcing, site planning, and a project conversation.
Included in the math
Usage × supply × reserve × growth
Your inputs are converted into one target capacity so you can compare the result with commercially available tank sizes and your delivery plan.
Not decided by the math
Final tank and site approval
Nominal tank availability, usable operating volume, delivery practices, site layout, listing, containment, permitting, and AHJ requirements still need separate review.
Worked example
Suppose a site uses 700 gallons per week, wants 14 days of supply, adds a 15% reserve, and assumes no near-term growth. Average use is about 100 gallons per day. Fourteen days is about 1,400 gallons, and the reserve raises the planning target to roughly 1,610 gallons. That does not mean “buy a 1,610-gallon tank.” It means the next step is to compare practical nominal sizes, delivery cadence, usable volume, and site constraints around that target.
FAQ
Common sizing questions
Should I size from average or peak use?
Use an input that represents the operating condition you actually need the tank to support. If consumption varies materially, test both normal and peak scenarios rather than assuming one average tells the whole story.
Does the result include unusable volume?
No. The result is a planning target based on consumption. Final selection should account for the usable operating range and the characteristics of the specific tank and dispensing setup.
Is a larger tank always better?
No. More capacity can change footprint, delivery behavior, capital cost, fuel turnover, and the questions an AHJ or regulator may ask. Capacity should follow the operating need and site—not a “bigger is safer” assumption.
Can this calculator determine permit requirements?
No. Capacity is only one project input. Use the permit workflow and jurisdiction guides to identify the agencies, code layers, and site-specific questions that still need confirmation.
Continue the project
Turn the sizing result into a complete tank plan.
Buyer guide
Diesel Storage
Put capacity in the context of deliveries, pumps, containment, monitoring, and operating needs.
Site
Site Planning Checklist
Check footprint, truck access, protection, foundation, venting, dispensing, and containment.
Approvals
Permit Workflow
Organize the fire/AHJ, SPCC, state-program, zoning, building, and electrical questions.