# PackCalc > PackCalc is a free packaging engineering calculator suite. It provides browser-based tools for corrugated box design, case packing optimization, pallet loading, load stability analysis, accelerated aging, and statistical process control. Built for packaging engineers, logistics teams, and operations professionals. ## Tools - [Box Strength Calculator](https://packcalc.com/tools/box-strength): Calculate corrugated box compression strength (BCT) from ECT, board caliper, and box dimensions using the McKee formula. Includes stack safety analysis, required ECT estimation, and humidity derating. - [Case Packing Calculator](https://packcalc.com/tools/case-builder): Calculate how many cartons fit in a known case, or design optimal case dimensions for a target pack count. Includes orientation analysis and cube utilization. - [Pallet Calculator](https://packcalc.com/tools/pallet-fit): Calculate how many boxes fit on a pallet with TI/HI output. Supports GMA, EUR, and custom pallets. Column, interlocking, pinwheel, and hybrid patterns with 3D visualization. - [Carton Builder](https://packcalc.com/tools/carton-builder): Browse and compare FEFCO-style carton, mailer, tray, folder, carrier, sleeve, and light shipper structures; configure dimensions and material/caliper guidance; generate preliminary carton specification sheets; and pass case-fit dimensions to Case Builder and Packaging Systems. - [Pallet Load Stability Calculator](https://packcalc.com/tools/pallet-load-stability): Calculate pallet load center of gravity height, tilt angle resistance, and lateral g-force thresholds. Screen against EN 12195-1 and EUMOS 40509 transport stability standards. - [ASTM D4169 Test Plan Generator](https://packcalc.com/tools/astm-d4169): Build ASTM D4169 distribution simulation test plans. Select distribution cycle (DC-1 through DC-17), set assurance level, and get calculated drop heights, compression loads, and vibration profiles. - [Statistics Suite](https://packcalc.com/tools/statistics): Descriptive statistics, capability analysis (Cp, Cpk, Pp, Ppk sixpack), Gage R and R studies, and acceptance sampling plans for packaging quality data. - [Accelerated Aging Calculator](https://packcalc.com/tools/accelerated-aging-calculator): Calculate ASTM F1980 accelerated aging test duration from target shelf life using the Q10 method. Outputs acceleration factor, test duration, and pull-date schedule. - [Absolute Humidity Calculator](https://packcalc.com/tools/absolute-humidity-calculator): Convert temperature and relative humidity to absolute humidity in grams per cubic meter. Uses the Magnus-Tetens approximation for saturation vapor pressure. - [Dew Point Calculator](https://packcalc.com/tools/dew-point-calculator): Calculate dew point temperature from ambient temperature and relative humidity. Used for condensation risk assessment in packaging environments. - [Shipper Builder](https://packcalc.com/tools/box-specifications): Browse and compare FEFCO-style corrugated shipper structures; configure inside or outside dimensions, payload weight, and board grade; generate preliminary outer shipper specification sheets; and pass outside dimensions, gross weight, and board data to Box Strength, Pallet Fit, and Packaging Systems. - [Unit Converters](https://packcalc.com/tools/converters): Convert between length, weight, area, and volume units used in packaging and supply chain. Includes industry-specific conversions. ## Methodology and Reference Each tool page includes a detailed methodology section explaining the engineering approach, formulas, assumptions, worked examples, common mistakes, and frequently asked questions. - [How McKee Formula Works](https://packcalc.com/tools/box-strength#learn): BCT prediction from ECT, caliper, and perimeter. Includes humidity derating, stacking safety factors, and the relationship between ECT and burst strength. - [Pallet Loading Methodology](https://packcalc.com/tools/pallet-fit#learn): How cases per pallet are calculated, TI/HI notation, pattern types (column, interlocking, pinwheel, hybrid), footprint and cube utilization, overhang handling, and standard pallet sizes. - [Case Packing Methodology](https://packcalc.com/tools/case-builder#learn): Internal vs external dimensions, wall thickness, orientation rules, packing efficiency metrics, and design-for-quantity optimization. - [Accelerated Aging Methodology](https://packcalc.com/tools/accelerated-aging-calculator#learn): ASTM F1980 Q10 method, Arrhenius relationship, chamber temperature selection, and limitations of accelerated aging. - [Pallet Load Stability Methodology](https://packcalc.com/tools/pallet-load-stability#learn): Center of gravity calculation, tilt angle geometry, lateral force resistance, and EUMOS 40509 screening. ## Resource Articles - [FEFCO Box Styles Guide](https://packcalc.com/resources/fefco-box-style-codes-explained): Reference for FEFCO-ESBO corrugated box style codes including 0201 RSC, 0203, 0427 mailers, and all major style families. - [Corrugated Cardboard Grades](https://packcalc.com/resources/corrugated-board-grades): Flute profiles, liner and medium specifications, ECT vs burst strength, and 32 ECT board selection. - [SBS vs CUK vs CRB Paperboard](https://packcalc.com/resources/understanding-carton-materials-sbs-cuk-crb): Comparison of paperboard substrates for folding cartons covering stiffness, print surface, and recycled content. - [Box Compression Testing Guide](https://packcalc.com/resources/complete-guide-box-compression-testing): TAPPI T804, ASTM D642, McKee estimates, conditioning, and safety factors for box compression testing. - [Pallet Load Stability Physics](https://packcalc.com/resources/pallet-load-stability-physics-tilt-angles): Tilt angle geometry, lateral vs longitudinal forces, and EUMOS 40509 test method. - [Safety Factors in Corrugated Design](https://packcalc.com/resources/safety-factors-corrugated-design): How to apply stacking, environmental, and handling safety factors to corrugated box design. - [Freight Class, Density, and NMFC Codes](https://packcalc.com/resources/freight-class-density-nmfc-codes-explained): How freight density affects NMFC classification and LTL shipping cost. - [Dimensional Weight Guide](https://packcalc.com/resources/dimensional-weight-dim-vs-actual-weight-guide): DIM weight calculation for UPS, FedEx, and carriers. When actual weight vs dimensional weight applies. - [How to Calculate Boxes per Pallet](https://packcalc.com/resources/how-to-calculate-boxes-per-pallet): Step-by-step method for calculating cases per pallet, with imperial and metric worked examples, pattern variations, and common constraint traps. - [TI HI Calculator Explained](https://packcalc.com/resources/ti-hi-calculator-explained): Reference guide to TI HI notation, how cases per layer and layers per pallet are calculated, and how pallet sheets use the notation. - [GMA vs EUR Pallet Sizing Guide](https://packcalc.com/resources/gma-vs-eur-pallet-sizing-guide): Dimensions, weight ratings, container loading, and compatibility rules for GMA 48 x 40 and EUR 1200 x 800 pallet standards. ## Optional - [PackCalc Homepage](https://packcalc.com/): Connected carton-to-pallet workflow, Packaging Systems, scenarios, and reports. - [Pricing](https://packcalc.com/pricing): Free tier, Pro, and Team plan details. - [All Tools](https://packcalc.com/tools): Complete tool directory. - [Resources](https://packcalc.com/resources): All packaging engineering articles and guides.