Forklift capacity is the total weight a machine can safely hold at a given time. While most forklifts come with a data plate listing their estimated capacity, this figure isn’t always accurate. According to a 2018 report by the Occupational Safety and Health Administration (OSHA), up to 62,000 workers suffer forklift-related injuries a year. In fact, carrying too heavy a load is one of the leading causes of forklift accidents.
Calculating forklift load capacity takes time and expertise. Operators have to consider factors like lift height, attachment weight and their machine’s condition. Taking these details into account will maximize safety on a work site and ensure your device has the longest possible service life.
How Much Can a Forklift Lift?
Depending on the model, forklifts can haul between 3,000 and 158,000 pounds.
When looking at the total mass a forklift can carry, you want to consider its rated capacity and net capacity. Rated capacity refers to the maximum weight listed on a forklift’s data plate. Generally, rated capacity encompasses a recommended weight range, not a hard limit. De-rated capacity is how much load capacity drops when old devices, unstable terrain or other factors hamper performance.
Net capacity, or payload capacity, is the actual weight a forklift can carry. Net capacity accounts for de-rated capacity, mast type, attachments, forklift weight and any modifications. Depending on the circumstances, rated capacity and net capacity may differ.
Forklift Capacity Chart
Experienced operators can estimate the lift capacity of a forklift based on its model. A machine’s load capacity correlates to its power source and size. The below table outlines the rated capacity of different forklift models:
| Forklift Load Capacity | Forklift Model | Rated Capacity | |||
| Electric 3-Wheel | 5,000 lbs | ||||
| Electric 4-Wheel | 12,000 lbs | ||||
| Internal Combustion – Cushion Tire | 15,000 lbs | ||||
| Rough Terrain Forklift | 35,000 lbs | ||||
| Internal Combustion – Pneumatic Tire | 36,000 lbs | ||||
| Internal Combustion – Counterbalance | 158,000 lbs | ||||
What Affects Lift Capacity?
Sometimes, determining lift capacity takes expertise and thoughtful calculation. Forklift sizes, load distribution and your device’s condition all affect its maximum capacity. The main factors to consider are:
Load Center
A forklift’s load center is the horizontal distance from the vertical face, or front of the forks, to the center of gravity of your load. In general, the load center of a forklift is 2 feet from the face of your forks or the center point of a 48-inch pallet. Operators who don’t center their loads at this position lower their carrying capacity. The term “load capacity” describes the total weight a forklift can haul at its ideal load center.
Forklift Dimensions
Forklift weight and size both factor into lift capacity. As a general rule of thumb, larger machines will carry heavier loads. Forklift dimensions affect the amount of leverage a device uses to lift heavier loads. Operators should also remember that larger forklifts run a greater risk of tip-overs and steering issues on unstable terrain.
Lift Height
The height at which a forklift carries its load affects maximum capacity. At higher lift heights, forklift load capacity decreases, and because higher loads increase instability, OSHA recommends that operators suspend their loads as close to the ground as possible.
Attachments
While forklift attachments let devices carry a wider array of materials, they also affect their capacity. As a result, teams must always subtract the weight of an attachment from a machine’s rated capacity. Attachments can also shift a forklift’s center of gravity. Depending on the haul, this makes finding the load center more difficult.
Forklift Condition
The better a forklift’s condition, the more it can lift at a given time. Wear and tear on tires, forks and internal components hampers a machine’s ability to function. As a result, older forklifts that need service and upkeep provide a lower net capacity.
How Is Forklift Capacity Calculated?
While the above chart breaks down every variable to consider, you can describe forklift weight capacity in even simpler terms. To calculate a device’s actual net capacity, start with this formula: Net capacity = X-Y/Z
To calculate X, multiply a forklift’s rated capacity in pounds (A) by the distance in inches from the front wheel center line to the front of forks (B) plus its rated load center measured in inches (C). So, X = A(B+C).
To determine Y, multiply the weight of an attachment in pounds (D) by the distance in inches from the front wheel centerline to the truck carriage face (E) plus an attachment’s horizontal center of gravity measured in inches (F). In other words, Y = D(E+F).
To calculate Z, add the distance from the front wheel centerline to the carriage face (E), the distance in inches from the carriage face to the rear face of the load (G) and the distance from the rear face of a load to the center of a load (H). As such, Z = E+G+H.
Forklift Capacity Calculation Example
With the formula in mind, consider a forklift with the following dimensions and weight:
- A = 5,000 pounds
- B = 19 inches
- C = 20 inches
- D = 770 pounds
- E = 17 inches
- F = 9 inches
- G = 7 inches
- H = 23 inches
Net capacity = 5,000(19+20) – 770(17+9) / 17+7+23
Net capacity = 195,000 – 20,020 / 47
Net capacity = 3,722 lbs
Because of the load’s size and weight distribution, the forklift’s net capacity is lower than the rated capacity. However, an operator could increase the net capacity by changing the forks’ angle and readjusting the load.
What Happens When You Exceed Maximum Forklift Weight?
Going above a forklift’s load capacity exposes the machine to damage and jeopardizes employee safety. As a result, operators should get forklift certified and learn how to avoid this at all costs. The amount of time saved by carrying a heavy load isn’t worth the price of damage and injury. Exceeding your forklift’s maximum capacity presents safety hazards such as:
- Tip-overs: Carrying a heavy load on unstable terrain may cause a forklift to tip over.
- Steering failure: Carrying materials above maximum capacity may make it hard to properly steer forklifts.
- Spilled loads: Going above a machine’s net capacity may cause materials to slide off the forks.
- Equipment damage: Hauling an exceedingly heavy load can damage a forklift’s mast, tines and attachments.
- OSHA fines: Any teams caught ignoring OSHA safety regulations may face legal and financial penalties.
Getting the Best Forklift Load Capacity
When it comes to forklifts, there is no one-size-fits-all model. Instead, technicians build different machines to carry loads of various sizes. Choosing the right model comes down to two questions: How much does a forklift weigh and can you find a model capable of lifting more than the required capacity for a project?
When it comes to getting the right equipment, renting is the best option. Renters provide a variety of forklifts at different weights and carrying capacities. Because of that, your team will be able to find the perfect model for your project. To err on the side of safety, you can also choose a model with a higher rated capacity than you expect to need.
So long as you stay within a forklift’s maximum capacity, there’s no better piece of equipment to carry materials across a work site. When you partner with BigRentz, you can rent a forklift with the perfect capacity for your next project.
