Estimating Guides
Learn the formulas and methods behind accurate material takeoffs
These guides explain how to estimate materials for common construction trades. Each guide covers the formulas our calculators use, industry standards, and tips from experienced estimators.
Acoustical Ceiling Estimating
Grid components, tile counts, seismic requirements, and hanger spacing for suspended ceilings.
Paint Estimating
Coverage rates by substrate, coat calculations, and gallon packaging for commercial painting.
RT60 Acoustics
Sabine formula, NRC values, reverberation time targets, and treatment selection for room acoustics.
Drywall Estimating
Sheet counts, joint compound, tape, screws, and waste factors for drywall installation.
Coming SoonFlooring Estimating
Material quantities for carpet, VCT, LVT, and sheet goods with waste calculations.
Coming SoonWhy These Guides?
Most estimating software is a black box—you enter dimensions and get numbers, but you don't know why. These guides show you the actual formulas so you can:
- Verify calculator results with manual spot-checks
- Adjust for unusual conditions the calculator doesn't cover
- Train new estimators on the fundamentals
- Defend your numbers when a GC questions your bid
Bookmark these guides for quick reference during takeoffs. Each one includes the exact formulas used in our free calculators.
Built-In Calculator, Converter & Shape Calculator
Every page on FreeTakeoff.tools includes a utility drawer with a quick calculator, unit converter, and shape calculator for complex areas. No need to switch apps or pull out your phone during a takeoff.
How to Open
Click the ⊞ button on the right edge of your screen. The drawer slides out and stays open while you work. Your calculator memory and drawer state persist across page loads.
Calculator Tab
- Basic operations — Addition, subtraction, multiplication, division
- Percentage — Quick markup and discount calculations
- Memory functions — M+ (add to memory), M- (subtract), MR (recall), MC (clear)
- Keyboard support — Use your number pad when the drawer is open (0-9, +, -, *, /, Enter, Escape, Backspace)
Convert Tab
Instant conversions between common construction units:
- Linear — Feet, inches, yards, meters, centimeters, millimeters
- Area — Square feet (SF), square yards (SY), square meters (SM), square inches
- Volume — Cubic feet (CF), cubic yards (CY), gallons
- Board feet — Enter thickness, width, and length to calculate lumber volume
Areas Tab — Complex Shape Calculator
Calculate area and perimeter for non-rectangular spaces. Select a shape, enter dimensions, and add directly to your active calculator.
Available shapes:
- L-Shape — Enter total width/length plus cutout dimensions
- T-Shape — Top bar and stem dimensions
- U-Shape — Outer dimensions plus center cutout
- Rectangle — Simple length × width
- Triangle — Base and height (calculates hypotenuse for perimeter)
- Circle — Radius only
How it works:
- Select a shape from the dropdown
- Enter dimensions in feet (diagram shows which measurement is which)
- Area and perimeter calculate automatically
- Click "+ Add to Calculator" to push the area to your ceiling or paint calculator
When you add a complex shape to the ceiling calculator, the correct perimeter is used for wall molding calculations—not the L×W approximation. This ensures accurate material quantities for L-shaped rooms, T-shaped lobbies, and other irregular spaces.
When the utility drawer is open and you're not typing in a form field, your keyboard works as a calculator. Press Escape to clear, Enter to calculate.
Request a Guide
Don't see the trade you need? We're adding new guides based on user requests. Send us a message with your suggestion.