Diesel Consumption Calculator

Example Data Table

Sample planning inputs and expected totals for one unit.

Formula Used

1) Work, idle, and standby liters

Work hours = Hours/day − Idle hours − Standby hours

Liters/day per machine = (Work hours × Work rate) + (Idle hours × Idle rate) + (Standby hours × Standby rate)

Total liters = Liters/day per machine × Days × Machines

2) Power-based work rate (optional)

Fuel mass (g/hr) = Power (kW) × Load factor × BSFC (g/kWh)

Work rate (L/hr) = (Fuel mass/1000) ÷ Diesel density × Field factor

3) Cost and emissions

Total cost = Total liters × Diesel price per liter

CO₂ (kg) = Total liters × CO₂ factor (kg/L)

How to Use This Calculator

1. Pick a method: direct fuel rate or power-based.
2. Enter machines, days, and total hours per day.
3. Add idle and standby hours for realistic duty cycles.
4. Provide work, idle, and standby fuel rates if using direct mode.
5. For power mode, input kW, load factor, BSFC, and density.
6. Set diesel price and currency for budget estimates.
7. Press Calculate, then export CSV or PDF if needed.

Professional Notes for Construction Planning

1) Why diesel tracking matters

Fuel is a controllable site cost. Measuring planned versus actual use highlights waste, supports accurate invoicing, and reduces shutdown risk from missed deliveries.

2) Separate work from idle time

Idle burn is often underestimated. Include warm-up, waiting for trucks, and operator breaks. Small idle reductions across a fleet can produce meaningful savings.

3) Match rates to real duty cycles

Manufacturer brochures show best-case values. Field rates vary with grade, soil, attachment choice, haul distance, and operator technique. Use site logs when available.

4) Use power-based estimation carefully

Power and BSFC methods work well for generators and steady loads. For changing loads, average the load factor over the shift and apply a conservative field factor.

5) Plan storage and delivery windows

Convert total liters into daily demand. Compare with tank capacity and supplier lead times. Add a buffer for weather delays and unplanned overtime.

6) Budget with unit price sensitivity

Run scenarios with low and high fuel prices. This helps you lock procurement decisions, negotiate contracts, and explain cost movement to stakeholders.

7) Include emissions in reporting

Many projects track greenhouse gases. A standard factor converts liters to kilograms of CO₂. Use consistent assumptions across reports to avoid mismatched totals.

8) Improve accuracy over time

After each week, replace estimates with measured receipts and hour-meter readings. Update fuel rates by equipment class and work type, then re-forecast remaining tasks.

FAQs

1) What is a good starting work rate for heavy equipment?

Start with the manufacturer’s average fuel burn, then adjust using your first week of receipts and hour-meter data. Always separate productive work and idle time.

2) Why does my idle fuel use look high?

Idle includes warm-ups, waiting, and hydraulic standby. High ambient temperatures, engine size, and PTO loads can increase idle burn beyond typical values.

3) Should I use liters or gallons?

Use the unit your supplier invoices. The calculator outputs liters and US gallons, so you can match procurement documents and site logs easily.

4) How do I choose a load factor for generators?

Estimate average electrical load divided by rated generator output. For mixed loads, average over the shift. Use a slightly conservative value to avoid under-ordering fuel.

5) What BSFC value should I use?

Use the engine data sheet if available. If not, a common planning range is 180–260 g/kWh for modern diesel engines under steady operation.

6) Does diesel density change results much?

Density mainly affects power-based conversion. Typical site variation is small, but cold temperatures and fuel blends can shift density slightly. Use a consistent assumption.

7) Can I export results for client reporting?

Yes. After calculation, export a CSV for spreadsheets or a PDF summary for approvals, daily reports, and procurement coordination.