Last updated 2026-11-12
Caster Load Capacity Chart: How to Calculate the Right Rating
Use our caster load capacity chart and calculation guide to choose the right caster load rating for trolley weight, uneven floors and safety margins.
A caster load capacity chart helps you compare models, but the printed rating is only useful when you calculate the load correctly. This guide explains caster wheel load capacity, the three-caster rule for four-wheel trolleys, safety margins and how to choose a JLS model rated 40–150 kg per caster.
Quick answer: the caster load capacity formula
Add the equipment weight, maximum payload and permanent accessories, then divide by the number of casters that can reasonably be expected to share the load. For a conventional four-caster trolley, use three load-sharing casters:
Minimum capacity per caster = total operating weight ÷ 3
The three-caster rule allows for uneven weight distribution. Add further capacity when impact, thresholds, speed or continuous operation demand it. For other wheel layouts, use an application-specific calculation rather than forcing the same formula.
What does a caster load rating mean?
A caster load rating is the maximum load assigned to one model under its stated test conditions. It is not a promise that every trolley, floor and duty cycle will produce the same service life. Wheel material, bearings, bracket design, mounting and operating conditions all influence the suitable choice.
- Rating per caster: compare the calculated requirement per wheel with the exact SKU rating.
- Total operating weight: include the empty equipment, maximum payload, shelves, batteries and fixed tooling.
- Real duty cycle: rolling speed, impacts, floor joints, gradients and washdown can change the selection.
How to calculate caster load capacity
1. Calculate total operating weight
Use the maximum weight during normal operation, not the empty trolley or an average payload:
Total operating weight = equipment + maximum payload + permanent accessories
2. Choose the load-sharing caster count
On a conventional four-caster trolley, divide by three. Uneven floors, thresholds and off-centre loads can reduce the load carried by one wheel. Do not apply this shortcut automatically to six-caster, tilt-cart or other special layouts.
3. Add an application allowance
The load-sharing calculation addresses uneven distribution, not every impact or shock. Increase the selected rating when the trolley crosses thresholds, carries dropped loads, moves continuously or works in another demanding duty cycle.
4. Compare the result with the exact model
Select a model whose rated load per caster meets or exceeds the adjusted result, then confirm wheel material, floor compatibility, mounting, overall height and test conditions.
Caster load calculation examples
Example in kilograms
| Equipment weight | 120 kg |
|---|---|
| Maximum payload | 180 kg |
| Total operating weight | 300 kg |
| Four-caster load-sharing calculation | 300 ÷ 3 = 100 kg per caster |
| Example allowance of 1.3 for the application | 100 × 1.3 = 130 kg per caster |
| Practical selection | A 150 kg model such as JLS-3-SBP, subject to mounting and floor checks |
The 1.3 allowance is an example, not a universal requirement. Impact severity and the manufacturer's test basis must still be reviewed.
Example in pounds
For equipment weighing 600 lb with a 400 lb payload and 50 lb of accessories, total operating weight is 1,050 lb. On a conventional four-caster trolley: 1,050 ÷ 3 = 350 lb per caster. Choose a model rated at least 350 lb per caster and add margin if the application involves shock, rough floors or continuous use.
Caster load capacity chart: representative JLS models
Use this chart to compare representative JLS light- and medium-duty casters. Ratings are per caster, not per trolley. The complete caster catalogue lists all 62 models and mounting options.
| JLS model | Wheel Ø | Tread | Mounting | Rated load per caster | Representative use |
|---|---|---|---|---|---|
| JLS-0-DHD | 50 mm / 2" | TPR | Top plate | 40 kg | Furniture, displays, light trolleys |
| JLS-3-SBPU | 75 mm / 3" | PU | Threaded stem | 120 kg | Workshop and logistics carts |
| JLS-3-SH | 100 mm / 4" | TPR | Threaded stem | 120 kg | Equipment frames and medical carts |
| JLS-3-SZH | 100 mm / 4" | PP | Threaded stem | 140 kg | Warehouse and industrial trolleys |
| JLS-3-SBP | 100 mm / 4" | PP | Threaded stem | 150 kg | Shelving, cabinets and workbenches |
| JLS-3-KCH | 100 mm / 4" | PP | Top hole | 120 kg | Warehouse racks and OEM frames |
Do not infer capacity from wheel diameter or tread material alone. Two models with the same diameter can use different brackets, bearings and test conditions. Always confirm the specification for the exact SKU.
Dynamic vs static caster load ratings
A dynamic load rating concerns a caster moving under stated test conditions. A static load rating concerns a stationary load under its own conditions. They are not interchangeable numbers, and one may not be supplied for every catalogue model.
Check which rating appears in the specification and ask for the relevant test data. A parked trolley can also experience uneven loading, so neither rating removes the need to consider floor condition and load distribution.
Caster safety factor and real-world conditions
There is no single caster safety factor that fits every application. Use the load-sharing calculation first, then review:
- Uneven floors and off-centre loads: use three load-sharing casters for a conventional four-caster trolley and size the heavily loaded corner where necessary.
- Impact and shock: allow additional capacity for dropped loads, dock plates, expansion joints and thresholds.
- Speed and continuous operation: provide travel speed, distance and daily duty cycle for review.
- Temperature and washdown: confirm the wheel compound, bearing and bracket finish against the actual environment.
- Powered towing or special layouts: request a separate assessment instead of assuming a manual-push rating applies.
Common caster load calculation mistakes
- Dividing a four-caster trolley's weight by four without considering uneven load distribution.
- Using empty equipment weight and forgetting the maximum payload or fixed accessories.
- Assuming a larger wheel automatically means a higher load rating.
- Confusing dynamic and static ratings or ignoring the stated test conditions.
- Choosing the exact calculated minimum without reviewing impact and duty cycle.
Caster selection checklist
- Equipment weight, maximum payload and accessories recorded.
- Wheel positions and load-sharing count confirmed.
- Floor condition, thresholds, speed and impact reviewed.
- Required capacity per caster compared with the exact SKU.
- Mounting, overall height, wheel material and test basis confirmed.
For a broader selection process, read the 7-step caster selection guide or use the technical load chart. If you need a model-specific recommendation, send the weight, caster count, floor and mounting details for a quote and drawing.
Frequently asked questions
How do you calculate caster load capacity?
Add the equipment weight, maximum payload and permanent accessories, then divide by the number of load-sharing casters. For a conventional four-caster trolley, divide by three and review whether the operating conditions require additional capacity.
Why divide by 3 when a trolley has 4 casters?
Uneven floors and off-centre loads can leave one caster carrying little or no weight. Dividing by three assumes the remaining casters support the load; it is a practical allowance, not a guarantee for every layout.
Does a larger caster wheel always have a higher load capacity?
No. Diameter mainly affects rolling, obstacle clearance and push effort. Capacity also depends on the wheel material, bearings, bracket and mounting design, so compare the exact model rating.
What is the difference between dynamic and static caster load ratings?
A dynamic rating applies to movement under stated test conditions, while a static rating applies to a stationary load under its own conditions. Use the rating and test basis specified for the exact model rather than treating the two as interchangeable.
What caster safety factor should I use?
There is no universal factor for every application. Start with the load-sharing calculation, then add margin for impact, thresholds, speed, continuous use or other demanding conditions. Ask for an application review when those conditions are significant.
Can I use the same formula for six-caster or tilt-cart layouts?
Not directly. A six-caster or tilt-cart layout distributes weight differently from a conventional four-caster trolley. Provide the wheel positions, total weight and operating conditions for an application-specific calculation.
Zehong Dong — Technical sales manager, JIELISHI
Handles OEM and distribution enquiries for casters — load and mounting selection, sample approval, custom tooling and the production follow-up in between.