Calculator Directory

Household Appliance Wattage Calculator Estimate daily and yearly electricity use and operating cost for a household appliance from wattage, or from amps and volts when wattage is not listed. Open → Construction Board Foot Calculator Calculate board feet for milled lumber from thickness, width, length, and quantity, or compare standing-log yield estimates across Doyle, Scribner Decimal C, and International ¼-inch log rules. Open → Construction Concrete Block Calculator Estimate CMU block count, mortar bags, sand, grout fill, and vertical reinforcement from wall dimensions, openings, block size, and waste allowance. Open → Construction Concrete Calculator Estimate concrete volume for slabs, columns, tubes, strip footings, and curbs; convert the result to cubic yards, cubic meters, bag counts, weight, and optional material cost. Open → Construction Concrete Mix Calculator Estimate concrete volume, ready-mix order quantity, and on-site cement, sand, aggregate, water, and bag counts from pour dimensions, mix grade, and waste allowance. Open → Construction Deck Board Spacing Calculator Find an even deck-board layout that keeps both outside margins equal, then estimate linear feet, joists, and fasteners from the same board count. Open → Construction Decking Calculator Estimate deck boards, linear decking, face screws or hidden clips, starter clips, fastener packs, and optional material cost for a deck surface. Open → Education Final Grade Calculator Find the final exam score needed to reach a target course grade, project a what-if final score, and optionally derive your current grade from weighted graded items. Open → Construction Floor Joist Calculator Check whether a common floor joist layout is within a planning span limit, then estimate joist count, hanger count, and lineal feet from the same dimensions. Open → Construction Framing Calculator Estimate studs, plate boards, opening side-stud allowances, waste-adjusted buy counts, and optional material cost for wood wall framing. Open → Business Freight Linear Feet Calculator Estimate LTL trailer linear feet from pallet count, loaded dimensions, stackability, mixed pallet sizes, and optional density-based freight class. Open → Education Grade Calculator Calculate a weighted course grade from syllabus weights, see how much of the course is already banked, and estimate what average is needed on remaining work. Open → Math Interquartile Range Calculator Calculate Q1, median, Q3, interquartile range, and 1.5 x IQR outlier fences from a pasted data set, with classroom and interpolated quartile methods. Open → Construction Linear Feet Calculator Convert a square-foot area into the running linear feet of flooring, planks, trim, siding, or boards you need to buy, then add a waste allowance so you order enough in one trip. Open → Construction Lumber Calculator Estimate boards to buy, board feet, lineal feet, waste allowance, and project cost for dimensional lumber orders. Open → Construction Lumber Weight Calculator Estimate lumber weight from species density, actual dimensions or board feet, piece count, moisture content, and pressure-treated condition. Open → Household Paint Calculator Estimate how many gallons and quarts of paint to buy for one interior room's walls, a ceiling, a whole exterior, or a primer coat — rounded up to purchasable cans so you never run short mid-coat. Open → Education Percentage Calculator Solve four percentage questions in one form: percent change between two values, percent of a number, percent difference between two values, and what percent one number is of another. Open → Construction Plywood Calculator Estimate plywood sheets, usable coverage, and optional material cost from project dimensions, sheet size, and waste allowance. Open → Construction Plywood Weight Calculator Estimate plywood sheet weight, pallet weight, and surface weight density from panel size, sheet count, grade density, and nominal or measured thickness. Open → Education Quiz Grade Calculator Convert a quiz, test, or assignment score into a percentage and letter grade from either wrong-answer counts or earned-versus-possible points. Open → Construction Rebar Calculator Estimate rectangular slab, wall, or footing rebar length, stock-bar count, approximate weight, and lap-splice length from dimensions, spacing, clearance, and bar size. Open → Education Semester Grade Calculator Project a semester grade from term/marking-period scores and a final exam, then see the final exam score needed for a target semester grade. Open → Household Solar Panel Calculator Estimate a home solar system size, panel count, roof area, annual generation, annual savings, installed cost, and simple payback period — or forecast yearly output from an existing array. Open → Everyday Speed Calculator Solve for speed, distance, travel time, or running pace with one average-speed form and 11-unit speed conversions (mph, km/h, m/s, knots, ft/s, ft/min, mi/min, yd/s, yd/min, in/s, cm/s). Open → Everyday Time Calculator Find elapsed time between two clock readings, add/subtract a duration from a start time, evaluate a duration expression, or do calendar-date arithmetic. Open → Household Water Hardness Calculator Convert calcium and magnesium readings into total water hardness, common hardness units, a USGS hardness category, and an optional temporary/permanent hardness split. A second mode estimates simple water-softener capacity, salt per regeneration, and days between regenerations from household use. Open →