Free Online Calculators
Finance, math, health, construction, and everyday tools in one searchable catalog.
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Polynomial Long Division Calculator
Pool Alkalinity Calculator
Pool Chlorine Calculator
Pool Heater Calculator
Pool Pump Runtime Calculator — Flow, Hours & Cost
Pool Salt Calculator
Pool Volume Calculator — Measure Gallons and Refill
Pregnancy Due Date Calculator — Weeks, IVF & Timeline
Priming Sugar Calculator — Batch & Bottle Solution Doses
Prop Slip Calculator — Measured Run Comparison
Quilt Backing Calculator — Yardage & Panel Layout
Quilt Binding Calculator — Strips & Fabric Yardage
Calculator descriptions
Polynomial Long Division Calculator
Divide polynomials exactly. Explore quotient, remainder and step-by-step subtraction in columns aligned by power, including fractions and missing terms.
Pool Alkalinity Calculator
Estimate sodium bicarbonate from measured pool alkalinity and your product label. Plan packages and recalculate from a fresh water test.
Pool Chlorine Calculator
Estimate a measured free-chlorine adjustment from your pool volume, test reading, chosen target and the exact strength unit on your product label.
Pool Heater Calculator
Plan pool heat-up time, the heater rating needed for a deadline, and optional gas or heat-pump cost using your measured water volume and cooldown.
Pool Pump Runtime Calculator — Flow, Hours & Cost
Plan daily pool-pump hours, circulated volume and energy from your actual flow and watts, with an optional second setting for a cleaner or other task.
Pool Salt Calculator
Work out how much pool salt to weigh, how many bags to buy and what remains. Preview salt levels and compare high-salt readings.
Pool Volume Calculator — Measure Gallons and Refill
Measure a pool’s inside dimensions, floor zones and waterline to estimate current gallons, full capacity and refill water.
Pregnancy Due Date Calculator — Weeks, IVF & Timeline
Estimate your due date and gestational age from last period, conception, IVF transfer, ultrasound age, or a known clinical due date, with a week-by-week visual timeline.
Priming Sugar Calculator — Batch & Bottle Solution Doses
Plan priming sugar for beer or measured sugar-solution doses for mixed bottle sizes. Account for residual CO2, final solution volume and dilution.
Prop Slip Calculator — Measured Run Comparison
Calculate apparent propeller slip from pitch, gear ratio, RPM and measured speed. Keep multiple runs, compare setups and save your measurement record.
Quilt Backing Calculator — Yardage & Panel Layout
Compare horizontal and vertical backing layouts, seam placement and fabric yardage. Get a proportional diagram, cutting list and printable plan.
Quilt Binding Calculator — Strips & Fabric Yardage
Plan straight-grain binding strips, account for joins and end allowance, and buy the right fabric increment. Includes a visual cutting plan and printable list.
