Forklift Lifting Capacity Calculator

Forklift Lifting Capacity Calculator

Standard is usually 24 inches.

Distance from fork face to center of the load.

Safe Lifting Capacity:

Note: This is an estimation. Always refer to the manufacturer's data plate.

function calculateForkliftCapacity() { var A = parseFloat(document.getElementById('ratedCapacity').value); var B = parseFloat(document.getElementById('ratedLoadCenter').value); var C = parseFloat(document.getElementById('actualLoadCenter').value); var AW = parseFloat(document.getElementById('attachmentWeight').value) || 0; var AT = parseFloat(document.getElementById('attachmentThickness').value) || 0; var resultDiv = document.getElementById('capacityResult'); var safeValueDiv = document.getElementById('safeValue'); var warningP = document.getElementById('capacityWarning'); if (isNaN(A) || isNaN(B) || isNaN(C) || A <= 0 || B <= 0 || C (A – AW)) { safeCapacity = A – AW; } safeValueDiv.innerHTML = Math.round(safeCapacity).toLocaleString() + " lbs"; if (C > B) { warningP.innerHTML = "⚠️ CAPACITY REDUCED: The load center is further than the rated distance."; } else { warningP.innerHTML = ""; } resultDiv.style.display = "block"; }

How Forklift Capacity is Calculated

Understanding forklift capacity is critical for warehouse safety and preventing tip-overs. A forklift operates on the principle of a seesaw (the lever principle). The front wheels act as the fulcrum.

The Basic Formula

To calculate the net capacity when the load center changes, we use the following physics formula:

New Capacity = (Rated Capacity × Rated Load Center) / Actual Load Center

Key Factors in Capacity

• Load Center: This is the horizontal distance from the vertical face of the forks to the center of gravity of the load. Most forklifts are rated at a 24-inch load center.
• Attachments: Adding a side-shifter, paper roll clamp, or fork extension reduces capacity because the attachment has its own weight and pushes the load further forward (increasing the load center).
• Lift Height: As the mast extends higher, the forklift becomes less stable. This calculator focuses on horizontal load center; always check your data plate for height-specific de-rating.

Example Calculation

If you have a 5,000 lbs forklift rated at a 24″ load center, but your pallet is 60 inches long (meaning a 30″ load center):

(5,000 lbs × 24 inches) / 30 inches = 4,000 lbs safe capacity.

OSHA Safety Standards

According to OSHA standard 1910.178, every forklift must have a legible data plate. Operators must never exceed the capacity listed. Operating a forklift with an oversized load center can cause the rear steering wheels to lift off the ground, resulting in a loss of steering control or a forward tip-over.

Safety Warning: This calculator is for educational purposes only. Never lift a load if you are unsure of the forklift's stability. If an attachment is added, the forklift must be re-rated by the manufacturer and a new data plate must be installed.