Aspect Ratio Calculator
Calculate image and video aspect ratios, find missing dimensions, and resize content without changing proportions.
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Browse practical online calculators and text utilities in one searchable directory.
Find the right tool for your task
ZemTools brings together free calculators and focused utilities for everyday calculations, construction estimates, electrical planning, time math and digital text tasks. Each tool is designed around a specific job, with clear inputs and practical results you can use on desktop or mobile.
Choose a category to narrow the list, or search by a tool name, material, measurement or problem. The directory below includes every currently available tool, with a direct link to its dedicated page.
Business Hours Calculator
Calculate working hours between dates with custom schedules and holidays, or add and subtract business hours to find a work-time deadline.
Open toolPaver Edge Restraint Calculator
Calculate open paver edge restraint, edging sections, straight and curved spikes, waste and optional material cost.
Open toolDeck Joist Blocking Calculator
Calculate joist blocking pieces, cut length, required lumber, stock boards, waste and optional fasteners for deck or floor framing layouts.
Open toolSod Staple Calculator
Estimate sod staples, landscape pins and turf staples from area, spacing, edges, seams and package size.
Open toolFind and Replace Text Online
Find and replace repeated text with case, whole-word, replace-all and replace-first controls.
Open toolWord Counter & Character Counter
Count words, characters, sentences, paragraphs and lines, with reading time and a live character-limit checker.
Open toolCase Converter Online
Convert text to uppercase, lowercase, title, sentence, camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE.
Open toolRemove Line Breaks Online
Join wrapped lines, preserve paragraphs, or replace line breaks with spaces and custom separators.
Open toolDuplicate Line Remover
Remove repeated lines while preserving order, with options for case, whitespace, blank lines and which occurrence to keep.
Open toolText Cleaner Online
Clean messy text by trimming lines, removing extra spaces, blank lines and duplicate lines, and normalizing line breaks.
Open toolPaint Calculator
Estimate paint needed for walls and ceilings, subtract openings, choose coats and coverage, and convert gallons and litres.
Open toolConduit Fill Calculator
Check raceway fill for mixed conductors and find the smallest practical conduit size.
Open toolWire Size & Voltage Drop Calculator
Plan cable size from load, voltage, distance, material and voltage-drop target.
Open toolFence Material Calculator
Estimate posts, rails, pickets or panels, concrete and optional material cost.
Open toolGravel Quantity & Ordering Planner
Estimate gravel volume, approximate weight, bags and optional project cost.
Open toolUUID Generator & Validator
Generate UUIDs, validate values and inspect version and variant information.
Open toolPilot Hole Size Calculator
Find practical pilot, clearance and countersink drill-bit starting sizes.
Open toolTime Calculator
Add and subtract hours, minutes and seconds, or find the time between values.
Open toolSignificant Figures Calculator
Calculate with significant figures and control precision without losing useful context.
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