03 — Tools / Load Calculator
Mezzanine load capacity calculator
Turn a documented uniform live-load rating and matching area into a distributed-weight calculation. Keep wheels, rack posts and machinery loads separate; this tool does not determine a rating.
Use the uniform live-load rating and the area it covers from the approved design documents. If either is unknown, get it confirmed before treating this calculation as relevant to your floor.
Do not substitute a supplier example or the carrying capacity of a forklift.
Do not combine areas with different ratings.
Uniform-load arithmetic only
Enter both documented values to calculate their product. This tool cannot determine an unknown rating or approve a loading arrangement.
Loading arrangement is unconfirmed. Identify any wheels, rack posts, machinery feet or other concentrated loads before using the result in a project discussion.
Do not add a safety-factor allowance, subtract assumed dead load from a documented live-load rating, or use unused area elsewhere to justify a concentrated load.
Understand ratings and point loadsPrepare your project brief with the printable planning checklist and quote comparison sheet
Methodology and limits
The calculation is rating (lb/sq ft) multiplied by area (sq ft). No code minimum, design safety factor or remaining-capacity estimate is calculated. Input limits are software bounds, not approved engineering ratings. The example is explicitly illustrative.
OSHA 1910.22(b) addresses the maximum intended load. Our load-capacity guide explains the difference between uniform, permanent and concentrated loading. PortaFab's project questionnaire asks separately for uniform loads, point loads and pallet-jack information.
For an existing floor, confirm the approved documents, applicable loading arrangement and condition with a qualified professional. Do not average wheel or rack-post forces over unused floor area. Use the planning checklist to prepare the information for that review.
Frequently asked questions
How do you calculate weight from a mezzanine PSF rating?
Multiply the documented uniform live-load rating in pounds per square foot by the area to which it applies. For arithmetic only, 125 psf times 2,000 sq ft equals 250,000 pounds uniformly distributed. This does not approve concentrated loading or verify an existing structure.
Can this tool tell me what rating my mezzanine needs?
No. It requires an existing documented rating and matching area. A qualified project designer must determine design requirements for the actual use and applicable rules. The example button supplies illustrative numbers only.
Can I use a PSF result to approve a forklift?
No. Forklifts, pallet jacks, rack posts and machine feet require a separate review of their actual loads and positions. This tool does not calculate their allowable capacity or a minimum forklift PSF rating.
Does OSHA 1910.22 require a capacity placard?
Its load provision requires walking-working surfaces to support the maximum intended load; it does not itself state a universal placard requirement. Check applicable local posting rules, approved documents and site requirements.
Should I subtract the floor's own weight?
Do not subtract an assumed dead load from a documented live-load rating. Confirm the terminology and included permanent loads with the designer; the tool does not convert an ambiguous total-load figure into an approved live-load rating.