Forklift Capacity: Load Centre, Load Chart and Derating Explained

What does a forklift’s capacity figure actually mean?

It is a promise made under fixed conditions. The Indian standard IS 6765 (Part 1):2003 separates two ideas that most brochures blur into one.

Rated capacity is the maximum load the maker says the truck can carry and stack with the mast upright, with the load’s centre of gravity at a standard distance from the forks, up to a standard lift height. That standard height is 3.3 m for most forklifts and 2.5 m for narrow pallet stackers and platform trucks. Rated capacity exists so that buyers can compare one truck with another on equal terms.

Capacity, sometimes called actual capacity, is what this particular truck can lift as it is equipped, with its own mast, its own forks or attachment, to its own maximum lift height. On a tall mast or with a clamp fitted, capacity is lower than rated capacity. It is the number that matters on the shop floor.

For counterbalance forklifts from 1,000 kg up to just under 5,000 kg, the standard load centre is 500 mm. Lighter trucks are rated at 400 mm and trucks from 5,000 kg to 10,000 kg at 600 mm; the types of forklift guide sets out the full table and the other truck classes. Above 10,000 kg the stability standard IS 4357:2004 allows 600, 900, 1,200 or 1,500 mm, because big trucks often carry long steel and timber.

What is the load centre, and how do you find it for your load?

The load centre is the distance from the front face of the fork arms (the vertical part the load rests against) to the load’s centre of gravity, its balance point. IS 6765 calls the horizontal distance Dh and the vertical one, measured up from the top face of the fork blade, Dv.

For an even load that is pushed fully back against the fork face, the load centre is half the load’s depth. A 1,000 mm deep pallet of cement bags has its centre about 500 mm out, which matches the standard. A 1,200 mm deep crate of evenly packed parts sits about 600 mm out, already past the standard.

Uneven loads are where people get caught. A motor crated with its heavy end away from the mast can have its balance point 800 mm out even though the crate is only 1,200 mm deep. If you know which end is heavy, put that end against the fork face. If you do not know, ask the sender, or lift a few centimetres and watch the rear wheels; a light, wandering steer is a warning. The Indian safety code IS 6305 (Part 1) tells operators to spread the forks wide and push them as far under the load as they will go, which keeps the balance point close to the mast.

Height counts too. A tall load, such as a stack of drums or a roll standing on end, has a high Dv, and a high centre of gravity makes the truck tip more easily when it brakes, turns or tilts.

Why does forklift capacity drop when the load sits further out?

Because a forklift is a see-saw. The front axle is the pivot. The load sits in front of it and tries to tip the truck forward; the counterweight, engine or battery sit behind it and hold the back down. What matters is not the weight alone but weight multiplied by its distance from the pivot. Double the distance and the same load pulls twice as hard on the front axle.

1. Dh, the horizontal load centre: from the fork face to the load’s balance point.
2. Dv, the vertical load centre: from the top of the fork blade up to the balance point.
3. The front axle, the pivot the truck tips about.
4. The counterweight, which holds the back of the truck down.
5. The load’s centre of gravity, pulling down in front of the pivot.

A shortcut many trainers use is to scale the rated capacity by the ratio of the two load centres: rated capacity times standard load centre, divided by your load centre. For a 3,000 kg truck rated at 500 mm, it gives the rough figures below.

The full calculation also counts the short distance between the front axle and the fork face, so on level ground the true forward-tipping figure comes out a little higher than the shortcut. That is why trainers like it: it leans to the safe side. But it says nothing about height, mast flex, tyres or slopes, and it can never be used to go above what the plate says. Treat it as a way to know when to stop and check the chart.

Why does capacity fall as the forks go higher?

A load held high is like a weight on top of a tall pole. The higher it goes, the further the balance point of the truck and load rises, so a smaller lean, bump or brake tips it. A tall mast also bends a little under load and tilts the load forward, which moves the load centre out just when the truck can least afford it.

That is why the safety code IS 6305 (Part 2):1980 makes the maker print the capacity at maximum elevation on the plate, not only the headline figure. Some makers design their trucks to hold full capacity higher than the 3.3 m standard. Godrej, for example, says its UNO series 3.0-tonne diesel forklift lifts its rated capacity up to 4.5 m (Godrej product page, November 2026). Above the height a truck is designed for, expect a smaller figure on the plate.

How you use the mast matters as much as how high it goes. IS 6305 (Part 1) tells operators to carry the load as low as is safe with the mast tilted back, to approach a stack with the mast tilted 3 to 5 degrees backward, to bring it upright only when the load is over the stack, and never to tilt forward with the carriage raised except to place or pick a load. Forward tilt at height is the quickest way to turn a legal load into an overload.

How is a forklift’s stability tested in India?

The capacity a maker prints has to survive a tilting-platform test set out in IS 4357:2004, the Indian method for testing counterbalance forklifts up to 50,000 kg. The truck stands on a platform with the test load on its forks, and the platform is tilted slowly to a set slope. The truck must not overturn. For trucks up to 10,000 kg, this platform test is the one that settles a dispute.

Two points come out of that table for a buyer. First, with the load at full height a forklift only has to stay upright on a 4% forward slope, about a 4 cm rise over a metre. A loading ramp or a broken yard can be steeper than that, which is why a raised load on a slope is so dangerous. Second, the test is run on a firm, smooth platform with the load centred, the tyres at the maker’s pressure and, on a rider truck, a 90 kg weight standing in for the operator. Soft ground, a worn tyre or an off-centre load all take away part of that margin. The solid tyre replacement guide explains when a worn tyre should come off.

The standard also defines normal use: stacking with the mast about vertical on firm, level, prepared ground, travelling with the load lowered and tilted back, and the load centred on the truck. Work outside those conditions needs a truck built and agreed for it.

How do you read a forklift capacity plate?

Every powered industrial truck must carry a durable identification plate in a prominent place, under IS 6305 (Part 2):1980 clause 3. Many operators call it the data plate or load plate. Here is what the clause asks for, and why each line matters.

Many makers print the plate as a small chart instead: a few lift heights down one side, a few load centres across the top, and a load in each box. To read it, find the row for the highest point the forks will reach, then the column for your load’s centre, and read the box. If your figures fall between two rows or columns, use the more cautious one, which means the next height up and the next load centre out. The clause also allows the load capacity to sit on a separate plate.

The battery line is easy to miss. If you are thinking of moving an electric truck from lead-acid to a lighter lithium pack, the plate’s minimum battery mass is the first thing to check, and the maker has to approve the change. The electric forklifts guide compares the two battery types, and the forklift battery guide covers charging and changeover.

A missing or worn plate is a fault, not a detail. IS 6305 (Part 1) puts it on the user to keep every name plate and marking in place and legible, and says the maker’s rated capacity must never be exceeded.

How do attachments change forklift capacity?

An attachment costs capacity twice. Its own weight comes off what the truck can lift, and its thickness pushes the load further from the mast, which raises the load centre. A side shifter moves the load a short distance forward; a paper-roll clamp, a drum clamp or a rotator moves it much further and weighs far more.

The Indian code deals with this in two places. IS 6305 (Part 2) clause 3.2 says every removable attachment carries its own plate with its mass, the distance of its centre of mass from the mounting face and its rated capacity, plus a warning that the actual load is limited by the truck or the attachment, whichever is less. IS 6305 (Part 1) says any change that affects capacity needs the maker’s approval and that the capacity plates must be changed to match. The UK’s L117 code of practice from the Health and Safety Executive (third edition, 2013) puts the same idea plainly: fitting an attachment needs a reduction in capacity, called derating, worked out with the maker or supplier, and a new capacity plate before the truck is used with it.

Fork extensions need extra care. They let you carry a long load, but they push the load centre out. Use only an extension the maker rates for your forks, and read its capacity from the plate. For regular long loads it is often better to buy a truck rated for a longer load centre. Godrej, for example, offers its G series 10-tonne diesel forklift with an optional rating of 10 tonnes at a 900 mm load centre for longer loads (Godrej product page, November 2026), against the 600 mm standard for that class.

Moving long or heavy loads around an uneven site? A telehandler with forks may suit the job better; see JCB 530-70 specifications and talk to a verified dealer.

How do you check a load against the plate before lifting?

Run these questions before any lift close to the limit. If any answer is “I do not know”, stop and find out.

1. What does the load weigh, including the pallet or crate? Use the invoice or the packing list, not a guess.
2. Where is its balance point? Measure the depth, find the heavy end and put it against the fork face.
3. How high does it have to go? Read the plate row for that height, not the headline figure.
4. Is an attachment fitted? Use the attachment plate and the truck’s capacity with that attachment, whichever is lower.
5. Is the floor firm and level where you will lift? If not, lower the load, move to level ground, or use a machine built for rough ground.
6. On a ramp, will the loaded end face uphill? IS 6305 (Part 1) says it should, going up and coming down.

Two rules from the same code are worth repeating because operators break them to save time. Never add extra counterweight, and never put people on the back of the truck, to lift more than the plate allows. And where a maker-approved work platform is used to lift people, the platform, its load and the people together must weigh no more than half the capacity shown on the plate.

Turning is the last trap: a sharp turn with a raised load can tip any forklift sideways. Godrej says its NEO electric forklift cuts speed by up to 30% in corners for this reason (Godrej product page, November 2026), but a slow, wide turn with the load low does the same job on any truck.

Does a telehandler’s load chart work the same way?

The idea is the same, but the chart is very different. A telehandler lifts on a boom that reaches forward as well as up, so its chart plots load against both height and outreach, and the safe figure falls quickly as the boom goes out. The Manitou MXT 840 K IND, for example, is listed with a 4,000 kg rated capacity, a 7,600 mm maximum lifting height and 4,230 mm of maximum outreach. Those three figures never apply at once; the chart shows what it carries at each point. The telehandler load chart guide explains how to read one, and crane load charts follow the same logic with a hook instead of forks.

On a building site, where a forklift’s small wheels would sink, most Indian contractors use a telehandler such as the JCB 530-70, listed with a 3,000 kg rated capacity. For yard and godown work, the material handling equipment page brings together the machines, tenders and news for that trade.

Lifting on rough ground or onto a slab? Compare telehandler models and load capacities and connect with a verified dealer.

If your loads keep landing beyond the standard load centre or above the standard height, buy a size up rather than working at the edge of the chart every day. Ask the dealer for the capacity chart of the exact mast and attachment being quoted, not the brochure figure. The forklift guide collects the rest of this series, and smaller indoor jobs may suit the machines in the pallet trucks and stackers guide; IS 6765 rates narrow stackers at a lower 2.5 m standard lift height.

Prices, specifications and features are indicative, vary by variant, location and date, and should always be confirmed with the official OEM or authorised dealer before any purchase decision. Capacity figures in this guide are examples or come from the standards and maker pages named; the plate and chart on your own truck always govern. DesiMachines is not liable for decisions taken on the basis of information that may have changed after publication.