Free CAD Tools — Viewers, DXF & Measure
Essential utilities for viewing, measuring, and converting CAD and DXF files. No signup required.
2D Drafting (14)
2D CAD Sketch Tool
Draw lines, rectangles, circles and arcs on a precision grid
Floor Plan Drawer
Sketch room layouts with walls, doors and windows
Technical Drawing Builder
Compose technical drawings with standard views
Engineering Drawing Template
Start from common engineering drawing templates
Detail Drawing Tool
Create enlarged detail views with callouts
Elevation Drawing Tool
Draft front, side and rear elevation views
Section View Builder
Define cut planes and build section drawings
Orthographic Projection Tool
Generate top, front and side projections
Isometric Drawing Tool
Sketch isometric pictorial views
Dimension & Annotation Tool
Add dimensions, leaders and notes
Line Weight Manager
Manage line weights and pen mapping
Title Block Builder
Create reusable drawing title blocks
Scale Bar Tool
Insert graphical scale bars for any scale
CAD Grid Planner
Plan grid spacing, snap and reference lines
Measurement & Geometry (12)
Distance Calculator (2D)
Compute distance between two 2D points
Area Calculator (polygon)
Calculate the area of any closed polygon
Perimeter Calculator
Calculate perimeter of polygons and curves
Angle Bisector Tool
Find the bisector of any angle
Arc Length Calculator
Compute arc length from radius and angle
CAD Unit Converter
Convert between mm, cm, m, inch and feet
Coordinate Input Tool
Enter and convert Cartesian / polar coordinates
Tolerance Stack-Up Analyzer
Analyze worst-case and RSS tolerance stacks
Thread Fit Calculator
Calculate thread fits and allowances
Hole & Slot Dimensioner
Dimension holes and slot features
GD&T Symbol Reference
Browse geometric tolerancing symbols
True Position Calculator
Calculate true position from deviations
Mechanical Engineering CAD (12)
Gear Ratio Visualizer
Visualize gear ratios and torque transfer
Cam Profile Designer
Design cam profiles from motion curves
Linkage Mechanism Simulator
Simulate four-bar and slider linkages
Stress Concentration Factor Reference
Look up Kt values for common features
Fit Tolerance Selector (ISO)
Pick ISO shaft / hole fits
Material Selection Guide (mechanical)
Compare common engineering materials
Fastener Reference Library
Browse standard fasteners and threads
Shaft Design Reference
Reference for shaft sizing and keys
Bearing Selection Guide
Select bearings by load and speed
Spring Rate Calculator
Calculate spring rate and deflection
Belt & Pulley Calculator
Compute belt length and pulley ratios
Chain Drive Calculator
Size chain drives and sprockets
Structural & Civil CAD (12)
Beam Span Calculator
Estimate beam deflection and span limits
Load Distribution Diagram Builder
Sketch load and reaction diagrams
Structural Section Properties Tool
Lookup I, S and Z for sections
Foundation Type Reference
Compare common foundation types
Column & Footing Sketch Builder
Sketch column and footing details
Retaining Wall Concept Tool
Concept layouts for retaining walls
Roof Load Calculator
Estimate dead and live roof loads
Wind Load Reference Tool
Lookup wind load pressures
Seismic Zone Reference
Seismic zone classification reference
Building Code Checklist
Common code compliance checklist
Staircase Design Tool
Design code-compliant staircases
Ramp Slope Calculator
Calculate ramp slope and run
Electrical & PCB Schematic (12)
Schematic Symbol Library Browser
Browse standard schematic symbols
Circuit Schematic Builder
Sketch circuit schematics with parts
Wire Gauge Reference
AWG wire gauge and ampacity reference
Electrical Load Calculator
Calculate electrical service loads
Panel Schedule Template
Generate a panel schedule layout
Single Line Diagram Builder
Build single line electrical diagrams
PCB Trace Width Calculator
Trace width from current and temp rise
PCB Impedance Calculator
Microstrip and stripline impedance
Via Current Capacity Calculator
Estimate via current handling
Component Footprint Reference
Common PCB footprint dimensions
SMD Component Identifier
Identify SMD package codes
PCB Design Checklist
Pre-fab PCB design checklist
Architecture & Planning (14)
Floor Plan Builder
Compose floor plans with rooms and walls
Room Layout Planner
Plan room layouts and furniture
Space Planning Tool
Allocate program areas across floors
Building Footprint Calculator
Compute footprint and coverage
Window & Door Placement Tool
Place windows and doors with clearances
Interior Elevation Sketch Builder
Sketch interior elevations
Site Plan Sketch Tool
Sketch site plans with setbacks
Zoning Setback Calculator
Calculate required setbacks
ADA Clearance Reference
ADA clearance dimensions reference
Parking Layout Tool
Lay out parking stalls and aisles
Furniture Layout Planner
Arrange furniture with clearances
Ceiling Height Reference
Common ceiling height requirements
Staircase Code Reference
Stair code rise / run reference
Fire Exit Path Planner
Plan code-compliant egress paths
Piping & HVAC (10)
Pipe Sizing Calculator
Size pipes from flow and pressure
Duct Sizing Calculator
Size HVAC ducts for airflow
HVAC Load Estimator
Estimate cooling and heating loads
Pressure Drop Calculator
Calculate friction pressure drop
Fluid Flow Rate Calculator
Flow rate from velocity and area
Pipe Material Reference
Compare common piping materials
Valve Type Reference
Browse common valve types
HVAC Equipment Selector Guide
Choose HVAC equipment by load
Refrigerant Properties Reference
Common refrigerant properties
Air Change Rate Calculator
Calculate ACH from CFM and volume
GD&T & Standards (10)
GD&T Symbol Reference (Standards)
Reference of GD&T symbols and rules
Flatness Tolerance Tool
Apply and check flatness tolerance
Cylindricity Reference
Cylindricity tolerance reference
Parallelism & Perpendicularity Guide
Orientation tolerance guide
Datum Reference Frame Builder
Build a datum reference frame
Feature Control Frame Builder
Compose feature control frames
Tolerance Grade (IT Grade) Reference
ISO IT grade tolerance tables
Surface Roughness Ra Reference
Surface roughness Ra reference values
Drawing Standards Comparator (ANSI vs ISO)
Compare ANSI and ISO drawing rules
CAD Standard Checker
Check drawings against CAD standards
CNC & Fabrication (12)
CNC Tool Path Planner
Sketch tool paths for milling and routing
Feed & Speed Calculator
Calculate feeds and speeds
Material Cutting Reference
Cutting parameter reference by material
Tooling Library Browser
Browse common cutting tools
G-Code Reference Viewer
Quick reference of common G/M codes
Machining Operation Selector
Pick the right machining operation
Chip Load Calculator
Compute chip load per tooth
CNC Material Thickness Guide
Thickness limits per process
Laser Cutter Power Reference
Laser power vs material reference
Waterjet Cutting Reference
Waterjet feed and pressure reference
Press Brake Bend Allowance Calculator
Bend allowance and deduction
Sheet Metal Flat Pattern Tool
Develop flat patterns for sheet metal
CAD Utilities (10)
Scale Factor Calculator
Compute scale factors between drawings
Drawing Title Block Generator
Generate a title block from inputs
Revision History Table
Build a revision history table
Parts List (BOM) Builder
Compose a bill of materials
CAD Layer Naming Convention Builder
Define layer naming conventions
Hatch Pattern Reference
Reference of common hatch patterns
Line Type Reference
Reference of standard line types
Drawing Number Generator
Generate drawing numbers from rules
Tolerance Notation Formatter
Format tolerance notations
Engineering Change Order Template
ECO template generator