36 focused calculators
Most online design tools stop at “how many tiles do I need.” InteriorLab goes further: acoustic comfort (RT60), biophilic scoring, Feng Shui Bagua mapping, circadian lighting schedules, paint sheen selection based on traffic and moisture, ergonomic desk fit, and 30 more. Every calculation runs entirely in your browser — no accounts, no uploads, no tracking.
Illustration only. Generated with inline SVG. No third-party assets used.
Every tool fits into a working problem designers actually face. Categories are editorial, not marketing — the grouping matches the workflow rather than the buzzword.
RT60, panel coverage, room mode flags.
Kelvin mood, WWR, hourly light plan.
Sheen wizard, undertones, VOC, scale.
Nature score, Bagua map.
Triangle, traffic, scale, clearances.
Rugs, art height, pendant drop, TV distance.
Tile, wallpaper, backsplash with waste.
Fan CFM, ACH, ergonomics, code checks.
Click any card to open the calculator. Each page documents assumptions, formulas, and limitations — no black boxes.
Calculates RT60 reverberation time using the Sabine equation and shows where your room sits on the speech-vs-music spectrum. Most calculators ignore low-frequency buildup — we flag it.
Tells you how much absorption coverage is needed to reach a target RT60, with a per-wall distribution hint.
Maps a Kelvin value to circadian impact and to the room mood it actually creates, not just “warm/cool.”
Builds an hour-by-hour Kelvin/lux plan tuned to melatonin and alertness cycles, with weekend variants.
Finds the daylight-energy trade-off, factoring orientation, glazing U-value, and shading.
Recommends paint finish across traffic, moisture, lighting angle, and substrate — not just a generic “eggshell for walls” chart.
Tests a hex code or RGB against warm/cool/neutral undertones and warns about the “greige trap.”
Estimates a room’s volatile organic compound load from selected finishes and furniture, with low-VOC swap suggestions.
Tells you whether a fabric/wallpaper pattern repeats too large or too small for your room — by wall area, not just pattern size.
Generates a 60-30-10 distribution from a base hex and a style descriptor, with contrast guardrails for accessibility.
Measures leg distances, flags traffic conflict zones, supports L/U/G/peninsula layouts — not just three points.
Plot furniture and let the tool flag choke points (any 60 cm path blocked) and shortcut gaps.
Overlays a 1.70 m human silhouette on a top-down room so you can see whether a 3-seat sofa actually fits.
Tells you which furniture arrangements survive a 90° door arc without getting hit.
Picks the minimum footprint for a chair + side table + lamp combo by reading posture.
Finds where a mirror best bounces natural light, with safety flags for opposite-the-bed placement.
Estimates the linear feet of hanging, shelf, and drawer you actually need based on your wardrobe mix.
Generates a hanger sheet with frame coordinates for rectangular, salon, linear, and diagonal layouts.
Recommends rug dimensions based on furniture arrangement: all-legs-on, front-legs-on, or floating.
Computes the centre-line height using the 145 cm rule, with furniture anchors and stairwell variants.
Solves for pendant height over a dining table, kitchen island, or entry — with sightline rules.
Recommends TV size and seating distance based on content type, viewing angle, and resolution.
Tells you the right insert size for a choppy, plump, or overstuffed look — by cover dimensions.
Picks the right door width and clearance per room, including ADA-compliant options.
Adjusts waste factor for straight, brick, herringbone, chevron, and basketweave patterns.
Accounts for pattern repeat (random, half-drop, full-drop) and roll width variants.
Calculates tile count with outlet subtraction, niche deductions, and pattern waste.
Recommends plank direction by room shape, light direction, and traffic flow.
Suggests transition strip type and length between two floor materials of different heights.
Sizes a fan by room volume and target ACH, with blade count and downrod hints.
Sizes a CADR by room area, ceiling height, and pollutant (allergens, smoke, virus).
Computes seat, desk, and monitor height by user height, with arm/eye ratios.
Checks rise/run ratio against IRC + 2×R+T rule, plus headroom clearance.
Verifies fixture clearances against IRC code and ADA standards side-by-side.
Most interior design “tools” on the open web are three thin widgets: a square-foot calculator, a colour picker, and a tile quantity estimator. They overlap with the calculator app on your phone and add nothing.
InteriorLab was built around a different brief. We asked: what does a working designer actually need to calculate that the existing tools don't do? The answer is a long tail of specific, unglamorous problems: Does this room pass RT60 for a home office? Should this pendant drop 65 cm or 80 cm above the island? What Bagua zone is the front door in? Is the rug too small for a sectional that floats in the middle of the room?
Each tool documents its assumptions up front — what formula it uses, what data it needs, where it breaks down. We don't sell the result as a substitute for professional advice: see the disclaimer below. We do try to catch the cases the standard tools miss, like pattern-repeat waste on wallpaper, or low-frequency RT60 in a room with a tile floor and a plaster ceiling.
InteriorLab is an independent, single-purpose toolbox for residential and small-commercial interior designers, architects, and serious DIY renovators. It exists because the open web is full of generic tile and paint calculators and short on the unglamorous calculations a real project requires.
Every calculation runs client-side in your browser. No measurements, preferences, or identifying data are stored on any server. No account, no login, no email collection. You can verify this with your browser’s network panel — there are zero outbound POSTs.
Who it’s for. Interior designers specifying finishes for clients, architects sketching room layouts, contractors double-checking a quote, homeowners running a renovation. The tools work for metric and imperial inputs (set per-tool).
What it can’t do. It can’t read your floor plan. It can’t replace an acoustic engineer’s measurement. It can’t certify that your stair meets local code — only flag whether the inputs pass standard checks. When a tool returns a number, treat it as a starting point for a decision, not the decision itself.
Limitations. Standard interior design references (NKBA, IRC, WELL, Terrapin Bright Green’s 14 Patterns, Sabine equation, CIE chromaticity) inform each tool’s formula. Coverage is broad but not exhaustive; if you need a calculation we don’t have, tell us — we add new tools quarterly.
Last updated: September 2026.
What we collect from you: nothing personally identifiable. Calculations run entirely in your browser. We do not store room dimensions, design choices, or any value you enter into any tool. We do not require an account.
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Third-party links. Outbound links to standards bodies, IRC, NKBA, or product reference pages are provided for context. We do not control those sites’ privacy practices.
Children’s privacy. This site is not directed at children under 13 and we do not knowingly collect any information from children.
Changes. Material changes to this policy will be posted here with a revised “last updated” date.
The calculators on InteriorLab are provided for general informational and educational purposes only. They use commonly cited formulas and reference values from interior design, acoustics, lighting, and building-code sources.
Nothing on this site constitutes professional design, engineering, architectural, medical, ergonomic, or building-code advice. Outputs should be treated as starting estimates for decision-making, not as certified measurements or approved specifications.
Always verify code compliance (IRC, ADA, NKBA, WELL) with your local authority having jurisdiction before construction. Always confirm acoustic and lighting performance with an on-site measurement or a qualified consultant before specifying products.
InteriorLab, its authors, and its publishers make no warranties about the completeness or accuracy of any calculation and are not liable for any decisions made based on tool outputs.