Do the math.
Skip the circus.
Eight tools and demos. No account. No server-side storage of tool inputs. Calculations and photos stay on your device unless you choose to export them. Start with the synthetic examples.
Tank chart builder.
You give us the measurements. We give you a mathematical estimate, not a certified calibration chart. Tank tilt, end caps and actual construction change the numbers.
Estimated gallons
| Dip (in) | Est. gal | Percent |
|---|---|---|
| 0.0 | 0.0 | 0.0% |
| 2.0 | 29.9 | 4.2% |
| 4.0 | 59.8 | 8.3% |
| 6.0 | 89.8 | 12.5% |
| 8.0 | 119.7 | 16.7% |
| 10.0 | 149.6 | 20.8% |
| 12.0 | 179.5 | 25.0% |
| 14.0 | 209.5 | 29.2% |
| 16.0 | 239.4 | 33.3% |
| 18.0 | 269.3 | 37.5% |
| 20.0 | 299.2 | 41.7% |
| 22.0 | 329.1 | 45.8% |
| 24.0 | 359.1 | 50.0% |
| 26.0 | 389.0 | 54.2% |
| 28.0 | 418.9 | 58.3% |
| 30.0 | 448.8 | 62.5% |
| 32.0 | 478.8 | 66.7% |
| 34.0 | 508.7 | 70.8% |
| 36.0 | 538.6 | 75.0% |
| 38.0 | 568.5 | 79.2% |
| 40.0 | 598.4 | 83.3% |
| 42.0 | 628.4 | 87.5% |
| 44.0 | 658.3 | 91.7% |
| 46.0 | 688.2 | 95.8% |
| 48.0 | 718.1 | 100.0% |
Do not use estimated charts for custody transfer, regulated measurement or a fill-to-capacity safety decision. For irregular tanks, calibration is required. A photo is not a measurement.
Fuel additive calculator.
Enter fuel gallons and your product's fuel-to-additive ratio. See the additive dose in both US fluid ounces and US gallons, for one load or each compartment.
1,500:1 means 1,500 US gallons of fuel per 1 US gallon of additive. Use the ratio specified for your product and conditions.
Use C1 for a whole load, or add separate compartments. Enter fuel to treat, excluding fuel that has already received its full dose.
Additive required at your ratio
1,500.00 fuel gallons ÷ 1,500 = additive gallons. One US gallon equals 128 US fluid ounces.
| Compartment | Fuel US gal | Additive US gal | Additive US fl oz |
|---|---|---|---|
| C1 | 1,500.00 | 1.0000 | 128.00 |
| Total | 1,500.00 | 1.0000 | 128.00 |
US fluid ounces measure volume, not weight. The ratio uses fuel volume, not total blended volume. Totals use unrounded calculations; displayed amounts are rounded.
This calculator does not choose a winter treatment rate or guarantee cold-weather protection. Follow the specific additive label for fuel compatibility, dose, mixing and temperature instructions.
Colorado off-road diesel tax savings check.
The rate snapshot includes $0.5976 per gallon in federal and Colorado taxes and fees on clear diesel. Qualifying dyed-diesel use avoids $0.5780 in this model. Put in your volume and supplier pricing to see what is worth investigating.
Rates checked November 6, 2026. Synthetic example inputs. Prices and differences display four decimals per gallon; calculations retain the published fee precision.
Your fuel
Enter fuel for qualifying off-road use, such as excavators, dozers, loaders or generators. A fuel purchase alone does not establish eligibility.
Use a delivered supplier quote that includes applicable fuel taxes and fees.
Colorado state sales tax generally exempts qualifying dyed diesel. Local rules can differ, including home-rule cities such as Aurora. Verify the applicable local rate and tax base; zero is an assumption.
Choose 0–12 whole months. This multiplies the same monthly gallons across that period; review actual purchases, use dates and claim deadlines separately.
Estimates update as you type. The local-tax model applies the entered percentage to the estimated dyed price before local tax; confirm how your locality calculates it.
What you could save
Going forward, per year
$13,872.00
Positive estimate; verify the costs before switching
- Per month
- $1,156.00
- Tax and fees avoided per gallon
- $0.5780
- Estimated dyed price before local tax
- $5.0220
- Modeled local tax per gallon
- $0.0000
- Net savings per gallon after local tax and premium
- $0.5780
Tax already paid: amount to review
- Colorado excise refund estimate
- $4,920.00
- Federal fuel tax credit estimate
- $5,832.00
- Total lookback estimate
- $10,752.00
2,000 US gal/month × 12 months = 24,000 US gallons under review. The estimate assumes every entered gallon was tax-paid and qualifies. It includes only the $0.2050 Colorado excise and $0.2430 federal credit, with no road/bridge fee refund or local-tax adjustment.
Where the money goes on a gallon of clear diesel
- Fuel and supplier margin: $5.0024/gal
- Federal excise: $0.2430/gal
- Colorado excise: $0.2050/gal
- Road and bridge fees: $0.1300/gal
- Paid on dyed too: $0.0196/gal
| Tax or fee | Rate ($/gal) | Effective period or basis | Paid on dyed? |
|---|---|---|---|
| Federal diesel excise eligible for the modeled credit | $0.2430 | Federal credit rate; verify qualifying use | No, for qualifying use |
| Federal leaking underground storage tank tax | $0.0010 | Federal rate; not included in savings | Yes; no savings modeled |
| Colorado special fuel excise | $0.2050 | January 2019 onward | No, for qualifying use |
| Colorado Road Usage Fee | $0.0600 | July 2026–June 2027 | No, for qualifying use |
| Colorado Bridge and Tunnel Impact Fee | $0.0700 | July 2025–June 2027 | No, for qualifying use |
| Colorado environmental response, PFAS and fuel impact fees | $0.0186 | October 2026–June 2027 | Yes; no savings modeled |
| Total modeled clear-diesel taxes and fees | $0.5976 | $0.5780/gal avoided for qualifying dyed use | |
The combined Colorado environmental response, fuel impact and PFAS fees total $0.018625 per gallon before display rounding. These fees can change with fund balances; this is a dated rate snapshot, not a live rate feed.
Before you switch or file
Colorado lookback. Each eligible purchase must be at least 20 gallons. Claims generally must be filed within 12 months after purchase and no more than once per calendar quarter. A fuel-tax refund permit and the approved exemption percentage can reduce the gross arithmetic shown here. Review the DR 7189 permit process and DR 7118 claim with your tax professional.
Federal lookback. Use actual tax-paid gallons that qualify under the applicable Form 4136 rules and tax-year instructions. Claim periods and prior credits matter; do not claim the same fuel twice. The months input does not determine whether a tax year or claim is still open.
Supplier and local costs. The model does not include a new tank, delivery minimums, storage, financing or other switching costs. Verify local exemptions, the tax base and the delivered dyed quote. A positive fuel-price estimate alone is not a purchasing recommendation.
Sources and rate check
Source links open in a new tab so you can check the guidance without losing these inputs.
Checked November 6, 2026: Colorado fuel tax and fee rates (opens in a new tab), Colorado Fuel Tax Guide (opens in a new tab), Colorado fuel-user refund rules (opens in a new tab), IRS Form 4136 and instructions (opens in a new tab), and Aurora sales/use tax guidance (opens in a new tab).
Temporary relief: IRS dyed-diesel FAQs (opens in a new tab), IRS reporting and recordkeeping relief (opens in a new tab), and Colorado Executive Order D 2026 020 (PDF) (opens in a new tab). Relief does not establish a general tax holiday; check the current notices for conditions and updates.
These inputs are calculated in this browser and are not saved or included in your Build Studio request. Adding the tool to a build shares only the tool selection.
Fuel load planner.
What happens to the axle weights if I load it differently? Edit the table and watch the load change.
Front to rear. Scroll sideways on narrow screens, or focus the diagram and use arrow keys. Liquid height shows loaded / rated gallons. Rated capacity is not an approved fill target.
Schematic only. Widths illustrate capacity, not actual compartment length or liquid center of gravity. Liquid shape, tank ends and surge are not modeled.
How to measure & entered distances
Steer to rear-group center: measure horizontally from the steer axle center to the midpoint between the two axle centers. For a tandem, use the halfway point between the two rear axle centers.
Center from steer: measure horizontally from the same steer axle center to each compartment's longitudinal liquid center of gravity for the planned fill. Use manufacturer data or a documented engineering simplification recorded in the profile notes. The middle of an irregular tank compartment is not necessarily its liquid center. Do not derive these distances from this diagram or start at the tank front or previous compartment.
Entered measurements: steer to rear-group center: 20 ft.
- C1: 0 US gal loaded; 0.0% of rated capacity; center from steer: 12 ft.
- C2: 0 US gal loaded; 0.0% of rated capacity; center from steer: 14.5 ft.
- C3: 0 US gal loaded; 0.0% of rated capacity; center from steer: 17 ft.
- C4: 0 US gal loaded; 0.0% of rated capacity; center from steer: 19.5 ft.
Axle-center definition: NHTSA draft test procedure, page 15.
Fuel Compartment Planner · Load Summary
Within entered planning thresholds Planning comparisons only. Verify at a certified scale.
Axle balancing unavailable — additional measurements required.
Axle estimates require every compartment center and confirmation that those distances are verified from the steer axle.
Updated load: 0.0 gallons, payload 0 lb, gross 19,000 lb.
Weight thresholds, margins & calculation notes
| Threshold | Entered limit | Estimate | Remaining margin | Status |
|---|---|---|---|---|
| Vehicle GVWR | 54,000 | 19,000 lb | 35,000 lb | Within entered threshold |
| Steer GAWR | 12,000 | Unavailable | Unavailable | Not evaluated |
| Rear axle-group GAWR | 40,000 | Unavailable | Unavailable | Not evaluated |
At least 90% of an entered limit triggers an approaching warning. This is a planning buffer, not a legal allowance. Unavailable is not a pass.
- Axle estimates require every compartment center and confirmation that those distances are verified from the steer axle.
- Only entered thresholds are compared. Missing ratings and registration limits have not been checked; within an entered threshold is not legal clearance.
- Some entered thresholds cannot be evaluated because the corresponding loaded weight estimate is unavailable.
- Federal axle benchmarks cannot be compared because axle estimates are unavailable.
- Federal reference benchmarks check only the entered single/tandem grouping and supplied tandem spacing. They do not evaluate the Bridge Formula, individual loads within a tandem, state exceptions, permits, tire ratings, or route restrictions.
- Remaining gallons are geometric capacity, not approved working fill capacity. Confirm product compatibility, actual density and equipment-specific working limits.
- Synthetic demonstration values are not manufacturer-certified equipment data. Replace and verify them before planning an actual load.
Compartment loads · front to rear
Edit any cell to update the load. Rated capacity is geometric volume, not an approved working fill target. Verify actual density and compatibility.
| Compartment | Capacity (gal) | Loaded (gal) | Product | Density (lb/gal) | Available (gal) | Fill % | Liquid weight (lb) |
|---|---|---|---|---|---|---|---|
| C1 | 1,000.0 | 0.0 | 0.0 | ||||
| C2 | 1,200.0 | 0.0 | 0.0 | ||||
| C3 | 1,200.0 | 0.0 | 0.0 | ||||
| C4 | 800.0 | 0.0 | 0.0 | ||||
| Total | 4,200.0 | 0.0 | US gallons / pounds | 4,200.0 | 0.0 | 0.0 | |
Approved working limits & compartment center measurements
Use actual longitudinal liquid center-of-gravity data or document a simplified fixed-center assumption in equipment notes. Diagram widths never determine centers. Distances start at the steer axle.
| Compartment | Approved working fill (gal) | Center from steer (ft) |
|---|---|---|
| C1 | ||
| C2 | ||
| C3 | ||
| C4 |
Compare load plans
Save a snapshot, then adjust quantities or an approved tandem position. Changing equipment evidence, products or density clears the comparison. Nothing is saved after a page reload.
Actual empty scale readings · entered separately
These are entered empty-condition readings, not calculated loaded reactions. Source: operator estimate.
- Steer: 9000 lb
- Rear group: 10000 lb
Equipment Weights & Registration
All fields below are optional. Use equipment labels, registrations and current scale tickets. Blank means unknown, not zero. Include the same driver, fuel, equipment and supplies in every tare measurement.
CSV profiles & load exports · local files only
Download the blank template, complete one equipment row, save as UTF-8 CSV and import it here. Required profile values include equipment type, compartment count, capacity and product. Keep the versioned header unchanged. Weight and geometry values may stay blank.
Up to five compartments and 128 KiB. Import replaces only the matching equipment draft after validation. Review reports for working loads and comparisons are separate from importable equipment profiles. No uploads or server storage.
Files are parsed in this browser only. Avoid client names, VINs, plates or sensitive identifiers.
Synthetic example loaded. Replace demonstration values with your equipment information.
Planning limits & authoritative references
Static reactions assume fixed longitudinal liquid centers. They do not evaluate surge, braking, cornering, dynamic stability, full tank geometry or changes in liquid center of gravity. Confirm manufacturer loading restrictions, outage, thermal expansion, tire and suspension ratings, state/local rules, route bridges and permits separately. Mixed-product compatibility is not verified. DEF or other products require approved dedicated equipment and procedures.
The federal comparisons are limited benchmarks. The Federal Bridge Formula is not calculated. A comparison within entered thresholds is not loading authorization.
Customer site capture.
Review or replace the synthetic sample. Details and photos stay in this browser until you choose a download or share them with an app. There is no site-record database or automatic email service.
Save or email this capture
The ZIP contains CSV, JSON and selected photos. JSON records photo filenames and details, without embedding image bytes.
Capture status
GPS is optional. Reloading or leaving this page clears the capture. Files you download or share are then controlled by you and the selected app.
Fuel reorder timer.
Basic consumption math, not telemetry and not a replacement for tank readings. Enter a buffer and delivery lead time. Then act before the phone rings.
Next decision
Place order within approximately 3.5 days to protect the reserve.
Estimated geometric headroom: 4,200 gal.
Assumes constant daily use. This is a planning model. Actual usage, tank tilt, outages and supplier capacity change the result. Geometric headroom is not a safe delivery quantity; respect the tank's working fill limit.
Prepare a supplier email
Choose up to three products and enter the quantities you want to request. Review the email, then download a draft to open in your email app.
The reorder estimate above does not set your order quantity. Confirm your actual requirements, tank working limits, product specifications and supplier arrangements before sending.
Gasoline choices use US pump octane (AKI). Confirm availability, ethanol content and product suitability with your supplier.
This page downloads a local .eml file. It sends no email and saves no request details. Opening drafts varies by email app; use the preview to copy the details if your app cannot open .eml files.
One-page SOP skeleton.
If it takes 17 pages to explain who checks the ticket, you're not helping. Start with the trigger, the owner, the steps, exceptions and the evidence.
Preview
Dispatch. Driver. Closeout.
See how a route moves from the dispatch desk to a driver and back. Try the working sample below, then check whether the delivered gallons and closing measurements agree.
1. Prepare the route
Load the sample orders and four-compartment truck. Send the prepared shift to the driver view beside the desk.
2. Record the work
Choose products and gallons by compartment, then record as many deliveries as needed. Capacity and product checks protect the load; dispatch quantities stay advisory.
3. Review the closeout
Enter independent closing measurements and return the closed shift. Dispatch can review delivered gallons, remaining fuel and variance flags.
Follow a five-minute sample run
- Select Load sample route, then Send to driver.
- In the driver view, open Load. Record C1: 900, C2: 1,100, C3: 1,050 and C4: 550 US gallons.
- Open Deliver and record 350 gallons from C1 to Synthetic Site A (S1).
- Open Closeout. Enter C1: 550, C2: 1,100, C3: 1,050 and C4: 550 gallons, then close the shift.
- Select Return closeout. Dispatch should show 350 delivered gallons and zero variance.
These figures apply to this sample run. If you change a load or delivery, the expected closing amounts change too. A matching closeout does not mean every planned stop was completed.
Have a dispatch JSON file? Open the driver view in a new tab, choose your JSON file under My Shift, review the preview, and load it. You can also resume an exported shift JSON file.
Switching Field Kit tabs keeps this run. A full-page demo starts a separate run. Downloads are optional and stay on your device until you choose to share them.
Every browser tool uses local calculations; no tool inputs are sent to an API. Production SOPs, field capture, records and dispatch workflows require authentication and secure integration. Choosing a tool in Build Studio shares the tool selection only; these calculations and site details are not part of the build request.