Warehouse Aisle Widths & Forklift Requirements
Aisle width is one of the most important decisions in laying out a warehouse. Too wide wastes space; too narrow is unsafe or rules out the equipment you have. There's no single correct width for each type of truck: it depends on the specific truck, the loads it handles and how it operates. This guide explains what determines aisle width, how the main types of equipment compare, and what to check before you fix a layout.
Why There's No Standard Aisle Width
The SEMA Code of Practice notes that truck manufacturers provide aisle recommendations for specific truck types and load sizes. Lifting capacity doesn't determine aisle width: two trucks with the same capacity can need very different aisles.
Aisle width is measured at the narrowest point between the racking or the stored loads, and it should be reassessed whenever the truck or the loads change.
Manufacturers commonly publish an Ast figure: the working aisle width needed for right-angle stacking with a specified load. It's calculated differently for different types of truck, and it only applies to the load size and orientation the manufacturer states.
What Determines Aisle Width?
- The complete load: its full dimensions and orientation. A standard EPAL Euro pallet is 1,200 × 800 mm, and whether it's carried lengthways or widthways on the forks changes the aisle needed. Include any goods or wrapping that overhang the pallet.
- Truck geometry: the truck's dimensions, turning circle and how it turns to face the racking.
- Attachments: such as side-shifts or fork positioners, which can change the truck's dimensions and its residual capacity.
- Operating method: whether the truck turns in the aisle, reaches or rotates its forks, and whether traffic is one-way or two-way.
- Clearances: the manufacturer's assumed operating clearances, plus the clearances needed between the loads and the racking.
Use the Manufacturer's Figures
Base aisle widths on the published figures for the named truck model you'll be using, with its stated pallet size and orientation and the manufacturer's clearance assumptions. Rules of thumb for broad truck categories aren't a reliable design specification.
How Equipment Types Compare
A general comparison of the main types of handling equipment:
| Equipment | How it works | Aisle space |
|---|---|---|
| Counterbalance truck | Turns the whole truck to face the racking. Can also work outdoors and load vehicles. | Generally needs the widest working aisles |
| Reach truck | The mast moves forward to place and retrieve the load, so the truck is more compact when turning. | Narrower aisles than a counterbalance truck |
| Double-deep reach truck | A reach truck specially equipped with extended reach to store and retrieve pallets two deep. | Check aisle width, reach and residual capacity for the model |
| Articulated truck | The front section pivots, so the truck turns the load into the racking rather than turning its whole body. | Often narrower than a reach truck; confirm for the model |
| Turret / VNA truck | Operator-controlled. The forks rotate to place loads on either side without the truck turning. Usually guided by rails or wires. | The narrowest aisles; needs transfer areas at the aisle ends and very flat floors |
| Pedestrian-operated stacker | Walk-behind or ride-on truck that lifts loads to height. | Varies by model; generally for lower lift heights and lighter duties |
| Powered pallet truck | Moves pallets near floor level. Doesn't place loads at height. | For moving loads and floor-level positions, not racking at height |
| Manual pallet truck | Hand-operated. Moves pallets near floor level. | For moving loads and floor-level positions, not racking at height |
This is a general guide only. Requirements vary between models and loads, so confirm the figures with the truck manufacturer or supplier.
Double-Deep Racking
Double-deep racking stores pallets two deep from a single aisle. It needs specially equipped handling equipment, such as a suitable double-deep reach truck; a standard truck can't reach the rear pallets. Confirm the aisle width, reach and residual lifting capacity for your loads and lift heights.
- Access: rear pallets can only be accessed when the corresponding front position is clear. This affects selectivity, stock allocation and replenishment.
- Capacity: any gain should be calculated against the alternative layout you're considering, including working aisles, cross-aisles and how you operate.
VNA Trucks and Automated Systems
Very narrow aisle (VNA) layouts usually use operator-controlled turret trucks, guided by rails or wires in the aisle. HSG76 covers these guided-truck arrangements. Guidance doesn't mean automation: an operator still drives the truck.
Automated storage and retrieval systems, such as stacker cranes, are a different type of system. Their aisle dimensions and heights are project-specific and come from the system supplier.
Traffic Routes and Pedestrians
Main routes, secondary aisles and pick aisles don't all need to be the same width, but each must suit the vehicles and people using it.
- Vehicle routes: HSG76 says routes must accommodate the vehicles using them safely. A particular width doesn't automatically make a route suitable for two-way traffic: assess the largest vehicles and loads, passing clearances, visibility, junctions and where pedestrians cross.
- Pedestrian routes: there's no single HSE minimum width. Base it on how many people use the route, whether they need to pass each other, accessibility and escape arrangements. HSE emphasises separating people and vehicles, with suitable barriers and controlled crossing points where needed.
Checks Before You Fix a Layout
- Actual clear space: allow for pallet and load overhang, guards, columns, doors and other projections.
- Cross-aisles and turning areas: specify these separately from the working aisles between the racking.
- Floor suitability: check the floor's loading, condition and levelness, and the truck supplier's flatness requirements.
- Lifting capability: confirm the truck's capacity at the required height, load centre and reach.
- Operational controls: operator familiarisation, pedestrian segregation, and a review whenever the equipment or loads change.
Let Us Plan Your Warehouse Layout
Our design team will look at how you work, your equipment, and how quickly goods move in and out, then recommend the right aisle widths and racking layout. We work with your lift-truck supplier so the proposed layout is checked against the actual equipment specification.
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