Methodology
How the calculators work, and their limits
The formulas and assumptions behind every calculator on this site, and the things a calculator cannot see.
General principles
- Planning estimates, not certified layouts. Results help you plan and compare options. They are not engineering, fire-safety or legal advice, and they do not replace a racking supplier, a truck manufacturer’s data or a qualified layout planner.
- Whole units only. Only whole pallets, bays and rows are counted, and results are rounded down.
- Detail grows with your input. Where a tool can work from less information, the result is labelled with the level of detail it is based on.
- The working is shown. Each calculator lists the steps and figures it used.
- Your figures stay with you. All calculations run in your browser.
What real capacity also depends on
- Building structure, columns and floor load rating
- Fire exits, emergency access routes, walkways and sprinkler clearance
- Door and dock positions
- Forklift turning and manoeuvring space
- Rack type, beam and upright load ratings
- Product characteristics: weight, crushability, stacking limits, temperature needs
- Operational rules: stock rotation, segregation, quarantine and safety procedures
- Local regulations, which always take priority
Tool by tool
| Tool | Method | Main assumptions |
|---|---|---|
| Storage & Capacity Planner | Area only: a repeating module of storage rows and aisles applied to the area after reserved space and a cross-aisle allowance. Length and width: whole rows packed across the floor (single rows at the walls, back-to-back rows between aisles) and whole bays or pallet slots along each row, after wall clearance, reserved space and cross aisles. Levels: ground level plus beam levels that fit below the clear height minus top clearance, limited by equipment lift height. New warehouse: positions needed per level, then the smallest building with the chosen length-to-width ratio that holds them. Count my existing racking: aisles × racked sides × bays per side × pallets per bay × levels, with a height check against the clear height and truck lift height. | Typical aisle and lift figures per equipment type (replaceable); level height = load + 150 mm clearance + 120 mm beam by default; reserved space kept as a strip across one end; default 10% reserved and 10% cross-aisle allowance. |
| Container Load Planner | Whole pallets on the container floor, trying both orientations and filling leftover length and width with turned pallets. The Automatic layout also runs a bounded search of block layouts and keeps the higher count. The result is the best count found by the calculator, not a proven maximum. Then layers, weight and volume checks. | Typical internal dimensions and payloads, which vary by container; overhang added on each side; mixed layouts need loading clearance. |
| CBM Calculator | CBM per carton = length × width × height in metres, × number of cartons. Container fit: products loaded largest carton first, in blocks from the back of the container, with smaller cartons filling the gaps beside and above; loading stops at the payload when every product has a weight. Mixed percentage mode: the mix is a share of cartons. For each possible total, cartons are split by the requested mix in whole cartons (largest remainder rounding) and tested with the same loading method; the result is the largest total that loads completely into one container. | Typical internal dimensions and payloads; cartons stay upright unless you allow them on their side; every carton can carry the cartons above it; no room left for handling at the doors; weight distribution is not checked. |
| Trailer Loading | Same floor-layout method as the container planner, for trailer sizes. | Typical trailer dimensions and payloads; axle loads are not checked. |
| Pallet Calculator | Cartons per layer: the carton footprint is packed into the pallet area with rows, turned blocks and one pinwheel pattern. This is the best count found, not a proven maximum. Layers = (maximum loaded height − pallet height) ÷ carton height, rounded down. Cartons per pallet = the lowest of the space, height, maximum-layers and weight limits. | No overhang; pallet sizes are rounded down and carton sizes rounded up; every layer is built the same way; with Any side, all cartons stand the same way; the weight limit is for the cartons only; stability and crushing are not checked. |
| Volumetric Weight Calculator | Volumetric weight = length × width × height in cm ÷ divisor, × number of packages. Chargeable weight = the higher of volumetric weight and actual weight, with optional rounding up of the shipment total. | The divisors offered (6000 air, 5000 express, 3000 road, 1000 sea LCL) are common starting points; each carrier sets its own divisor, measuring and rounding rules, and may round every package separately. |
| Stock Count Variance | Difference = counted − system; accuracy = items within tolerance ÷ items counted × 100. | Tolerance is your own stock policy. |
| Safety Stock Calculator | Statistical: safety stock = Z × √(L × σd² + d² × σL²), with lead time converted to the demand period (days ÷ 1, 7 or 30). Simple: (maximum daily usage × maximum lead time) − (average daily usage × average lead time). Reorder point = demand during lead time + safety stock, both rounded up to whole units. | Demand and lead time vary independently and roughly follow a normal distribution; service level is the cycle service level, not fill rate; stock is reviewed continuously. |
| Inventory Turnover Calculator | Turnover = cost of goods sold ÷ average inventory. Average inventory = (opening + closing) ÷ 2, or the closing value alone when no opening value is entered. Days of inventory = days in the period ÷ turnover. | Stock is valued at cost, in the same currency as the cost of goods sold; an average of two values can hide seasonal peaks. |
| EOQ Calculator | EOQ = √(2 × annual demand × cost per order ÷ holding cost per unit per year), then the cheaper of the two neighbouring whole numbers. Reorder point = daily demand × lead time + safety stock, rounded up. | Steady, known demand; a fixed cost per order; holding cost in proportion to the stock held; no quantity discounts; the purchase price is not included. |
Testing and corrections
Before a tool is published or changed, its results are checked against hand calculations and against unusual inputs such as zero, negative or very large values. If you find a result that looks wrong, please report it with the figures you entered. Confirmed errors are corrected and the page is updated.
Last updated: October 2026.