Everyday & dates

Age, dates, week numbers, hours worked, word counter, passwords, fuel and electricity costs, concrete and paint.

Age = today − date of birthAge Calculator Days = end date − start dateDays Between Dates Calculator Date + n daysAdd Days to Date Calculator Duration = end − start − breakTime Duration Calculator (Hours Between Times)V = L · W · TConcrete Calculator (Slab Volume & Bags)V = (A · n)/cPaint Calculator (How Much Paint Do I Need?)C = P · t · 365 · pElectricity Cost Calculator (kWh)C = (d · L/100 km)/100 · pTrip Fuel Cost Calculator (Gas Cost)words · characters · reading timeWord Counter & Character Counter Entropy = length × log₂(alphabet)Strong Password GeneratorISO 8601 week numberWeek Number Calculator (What Week Is It?)seconds since 1970-01-01 00:00 UTCUnix Timestamp Converter (Epoch)Σ (end − start − break)Time Card Calculator (Weekly Hours)H = 16 · ln(d) + 31Dog Age Calculator (Dog Years to Human Years)days left = date − todayCountdown Calculator (Days Until a Date)any date → weekdayDay of the Week Calculator (What Day Was It?)workdays = Mon–Fri − holidaysBusiness Days Calculator (Working Days Between Dates)time B = time A − UTC offset A + UTC offset BTime Zone Converter PM: add 12 hours (12 PM = 12:00, 12 AM = 00:00)Military Time Converter (12h ⇄ 24h)total = Σ h:mm:ssTime Calculator (Add & Subtract Hours, Minutes)decimal = h + min ÷ 60Hours & Minutes to Decimal Converter day = date − Jan 1 + 1Day of the Year Calculator (Day Number)birthday → sun sign · birth year → Chinese animalZodiac Sign Calculator (Star Sign & Chinese Zodiac)divisible by 4, except centuries not divisible by 400Leap Year Calculator (Is It a Leap Year?)1st year = 15 · 2nd = +9 · then +4 per yearCat Age Calculator (Cat Years to Human Years)area = length × width (sum of all rooms)Square Footage Calculatortiles = (area × (1 + waste))/(tile area)Tile Calculator (How Many Tiles Do I Need?)boxes = (area × (1 + waste))/(coverage per box)Flooring Calculator (Laminate, Vinyl, Hardwood)V = A · dMulch & Soil Calculator V = L · W · dGravel Calculator (Cubic Yards & Tons)sheets = (walls + ceiling − openings)/(sheet area) × 1.1Drywall Calculator (Sheets Needed)rolls = (perimeter ÷ roll width)/(strips per roll)Wallpaper Calculator (Rolls Needed)posts = ⌈L / spacing⌉ + 1Fence Calculator (Posts, Panels, Pickets)pitch = rise/run × 12 · θ = atan(rise/run)Roof Pitch Calculatorrisers = round(total rise ÷ ideal riser) · 2R + T ≈ 25 inStair Calculator (Risers, Treads, Stringer)BTU/h ≈ 20 × ft² × adjustmentsBTU Calculator (Air Conditioner Size)V = area × average depthPool Volume Calculator (Gallons & Liters)V = L · W · HAquarium Volume Calculator (Fish Tank Gallons)BF = (T(in) · W(in) · L(ft))/12Board Foot Calculator (Lumber)t = Q/IBattery Life Calculator (mAh)t = (8 · S)/RDownload Time Calculator PPI = (√(w² + h²))/(diagonal (in))PPI Calculator (Pixel Density)4K: diagonal ≈ distance × 0.84 (THX 40°)TV Size & Viewing Distance CalculatorW₂/H₂ = W₁/H₁Aspect Ratio Calculator (Resize Images & Video)new amount = amount × (new servings)/(original servings)Recipe Scaler (Adjust Servings)≈ 13 min per lb at 325 °F (15 if stuffed)Turkey Cooking Time Calculator (Roast & Thaw)D = rim × 25.4 + 2 × width × aspect / 100Tire Size Calculator (Compare Sizes)kW = (daily kWh)/(sun hours × 0.8)Solar Panel Calculator (How Many Panels?)n d s · each die 1…s with equal probabilityDice Roller (Roll Dice Online)age = (date − new moon Jan 6, 2000) mod 29.53 daysMoon Phase Calculator (Moon Tonight)bricks = (wall area)/((L + j)(H + j)) × 1.05Brick Calculator (Bricks per Wall)WC = 35.74 + 0.6215 T − 35.75 v^0.16 + 0.4275 T v^0.16Wind Chill Calculator (Feels Like Temperature)NWS Rothfusz regression of T and RHHeat Index Calculator (Feels Like in Humidity)T_d = (c · γ)/(b − γ) · γ = ln(RH) + (b T)/(c + T)Dew Point Calculator