Model struck and heaped bucket volumes with confidence. Convert to payload using density and swell. Plan cycles, passes, costs, and safe rated loads easily.
Struck capacity is the level-full bucket volume. Heaped capacity adds the mound above the cutting edge, commonly about 10–25% higher on general-purpose buckets. Choose a percent heap or an angle-based heap to match your site method.
Real buckets are curved and tapered, so simple L×W×H can overstate volume. Use Advanced geometry when you know floor length, back height, side-wall angle, and lip angle. With basic dimensions, apply a shape efficiency, typically 0.85–1.00, for curvature and wear. Options like teeth, spill guards, and extensions can change effective shape.
Fill factor converts theoretical capacity to what you actually carry. In easy digging with a skilled operator, fill can reach 0.95–1.10. In hard, blasted, sticky, or tight trenches, 0.75–0.90 is common. Adhesion and moisture multipliers represent cling and slump.
Quantities are often measured as bank cubic meters, while the bucket carries loose material. Swell factors typically range about 1.05 for gravel to 1.40 for broken rock, but confirm with site tests. The calculator reports loose and bank volumes for pay item alignment.
Payload per pass depends on effective loose volume and loose density. Typical loose densities span roughly 1.3–1.7 t/m³ for sand, 1.6–2.0 t/m³ for moist clay, and 1.7–2.2 t/m³ for crushed rock, varying by moisture and gradation. Compare payload to machine limits with margin.
Production is driven by cycle time and actual utilization. Excavator cycles often fall around 20–35 seconds in short swing work, while wheel loaders may run 25–45 seconds depending on travel distance and pile condition. Utilization commonly ranges 50–85% after delays and traffic. Use utilization as working minutes divided by available shift minutes.
Truck matching reduces queues and underloads. A practical target is loading near the truck’s legal payload while keeping distribution even. Passes are truck target payload divided by bucket payload, then rounded up. The calculator warns when a bucket payload exceeds your rated limit input.
Cost per unit combines production with hourly ownership and operating cost. Include fuel burn, operator cost, planned maintenance, and standby. Report cost per bank m³ for earthwork pay items, or cost per tonne for aggregate work. Save scenarios to compare buckets and materials. Include repair reserves and tire wear.
Use struck for level-full reporting and tight control. Use heaped when your spec or manufacturer uses a heaped standard. Keep the chosen method consistent across density, fill factor, and truck matching.
Start at 0.90 for average digging and adjust with site observations. Increase toward 1.00–1.10 for free-flowing material and short swings. Decrease toward 0.75–0.90 for hard digging, poor fragmentation, or tight working space.
Use lab or supplier data when available. If not, start with typical ranges and correct using actual truck scale tickets. Moisture and gradation can change density significantly, so recalibrate when conditions change.
Swell converts between bank volume in the ground and loose volume in the bucket. If swell is ignored, production in bank m³ can be overstated. Always report both loose and bank outputs when pay quantities are bank-measured.
Enter the machine or attachment rated payload and compare it to calculated bucket payload. If the payload exceeds the rating, reduce fill factor, choose struck capacity, or use a smaller bucket. Keep an additional safety margin for dynamic loading.
They are engineering approximations that capture taper and curvature effects better than a box model. Accuracy improves with measured internal dimensions and calibration against one known capacity. Use shape efficiency to tune results to your bucket.
Yes. Enter the truck target payload or volume and your cycle time. The calculator estimates passes, hourly production, and unit cost so you can compare bucket sizes and loading strategies that minimize underloads and waiting time.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.