Methodology

Methods behind all eight tools

Each released tool keeps measured geometry, editorial assumptions, and external comparison data separate. This record makes those boundaries reviewable.

How to read the record

Formulas transform the measurements entered in the browser. Editorial defaults are starting values, not recommendations. External sources support only the claims named in each row, and a dataset version changes when stored comparison data or assumptions change.

There is no guarantee of fit, supply, comfort, delivery, rental availability, or safe loading. Recheck physical dimensions and the current product, vehicle, or facility before spending money.

Methodology registry

Tool	Formula	Assumptions / range	Source / version / date	Last reviewed	Correction status / history
Rug Size Calculator & Visualizer	Maximum rug width = room width - 2 x border; maximum rug length = room length - 2 x border.	Rectangular room and centered footprint; editable 18-inch default border; nominal retail sizes vary by product.	Home Depot, Rug Sizes for Your Space. Dataset home-depot-us-2026-07-10-v1, accessed July 10, 2026.	July 10, 2026	Correction history: No corrections recorded. Initial release record for home-depot-us-2026-07-10-v1, July 10, 2026.
Curtain Size & Fullness Calculator	Coverage = rod span + left return + right return + overlap; flat width = coverage x fullness; panels = ceil(flat width / seller panel width).	Operable non-Ripplefold panels. Supported ranges: rod span 6 to 240 inches; side returns 0 to 24 inches each; center overlap 0 to 24 inches; seller panel flat width 6 to 240 inches; finished length 6 to 240 inches; fullness 1.0x flat through 3.0x. Editable 2x fullness and sample dimensions are editorial starting values; finished length is advisory.	The Shade Store guidance, IKEA ready-made method, and Designer Drapery Hardware coverage formula; accessed July 10, 2026. Method v1.	July 10, 2026	Correction history: July 10, 2026: aligned the published range contract with the calculator's 240-inch rod, panel, and finished-length limits, 24-inch return and overlap limits, and 1.0x flat fullness option.
Sofa Through Door Checker	For six straight orthogonal profiles, clearance = opening width or height - the mapped sofa dimension; removable leg height reduces sofa height only.	Rectangular clear opening and rigid straight profiles only; supported physical dimensions are 1 to 240 inches. No turn, compression, tilt arc, stair, landing, or labor model.	Editorial geometry method straight-orthogonal-v1; no external fit dataset. Reviewed July 10, 2026.	July 10, 2026	Correction history: July 10, 2026: recorded the calculator's 1-inch minimum and 240-inch physical limit for measured sofa and opening dimensions.
TV Size & Viewing Distance Calculator	For 16:9, image width = diagonal x 16 / sqrt(337); horizontal FOV = 2 x atan(width / (2 x distance)); target mode inverts the equation.	30-degree mode is a historical cinema threshold; 40 degrees is this tool's derivation from the THX 0.835 multiplier. Neither guarantees comfort or acuity.	SMPTE EG 18-1994 was withdrawn in 2003 and SMPTE no longer endorses it; it is retained only as a historical caveat. THX consumer guidance supports the multiplier. Accessed July 10, 2026. THX-derived method v1.	July 10, 2026	Correction history: No corrections recorded. Initial release record for tv-fov-method-v1, July 10, 2026.
Paint Calculator	Gross area = perimeter x height (or sum of wall areas); net area = gross - openings; paint before waste = net area x coats / label coverage; paint after waste = before-waste liquid x (1 + waste); purchased amount comes from the US container mix; leftover = purchased - after-waste liquid.	Editable 350 sq ft/gal coverage, two coats, 10% waste, and the US container set are editorial defaults. Supported ranges are 1 to 6 coats, coverage of 100 to 800 sq ft/gal, and waste of 0% to 30%; the exact product label governs coverage.	Sherwin-Williams paint calculator FAQ for typical coverage context; accessed July 10, 2026. Paint method v1.	July 10, 2026	Correction history: July 10, 2026: corrected the default coverage to 350 sq ft/gal, documented the tested ranges, and now reports separate pre-waste, after-waste, purchased, and leftover outputs.
Moving Box Calculator	Sum editable room template counts; tape = ceil(boxes / 12), labels = ceil(boxes / 20), paper = ceil(boxes / 8).	Room templates and all three supply ratios are editorial assumptions; physical inventory and special-item needs override them.	U-Haul box-category guidance supports categories, not template counts or ratios. Dataset 2026-07-10.1, accessed July 10, 2026.	July 10, 2026	Correction history: No corrections recorded. Initial release record for 2026-07-10.1, July 10, 2026.
Moving Truck Size Calculator	Raw volume = sum of rectangular item envelopes; planning volume = raw volume x (1 + allowance); compare with published cargo volume.	Furniture envelopes and the editable 15% allowance are editorial; cubic volume does not model loading, payload, weight, or vehicle shape.	U-Haul truck size comparison and current U-Haul box dimensions. Dataset 2026-07-10.2, accessed July 10, 2026.	July 10, 2026	Correction history: July 10, 2026: corrected the capacity dataset by adding the published U-Haul 29-foot truck at 2,057 cubic feet so loads above the 26-foot truck's 1,682-cubic-foot boundary retain a current comparison candidate.
Storage Unit Size Calculator	Occupied area = total rectangular item volume / usable stack height; required area = occupied area / (1 - aisle share), then screen item footprints.	Editable 5-foot stack height, 20% aisle share, and furniture envelopes are editorial; listed unit dimensions are nominal and location-specific.	U-Haul storage unit size guide and current U-Haul box dimensions. Dataset 2026-07-10.2, accessed July 10, 2026.	July 10, 2026	Correction history: No corrections recorded. Initial release record for 2026-07-10.2, July 10, 2026.