Epoxy Calculator

What Is an Epoxy Calculator?

An epoxy calculator is a tool that calculates epoxy volume based on:

• Surface length
• Surface width
• Coating thickness
• Mixing ratio
• Waste or porosity allowance

Instead of guessing or relying on rough charts, the calculator gives you an exact amount in gallons, liters, or milliliters. It also splits the total into Part A (resin) and Part B (hardener), based on the mixing ratio.

Why Accurate Epoxy Calculations Matter

Epoxy is not cheap. Mixing too little means stopping mid-project. Mixing too much means wasted material that cannot be saved.

Accurate calculation helps you:

• Avoid running out of epoxy halfway through
• Reduce leftover waste
• Maintain proper resin-to-hardener ratios
• Get consistent curing and finish quality

Even small mistakes in thickness or ratio can lead to soft spots, bubbles, or curing failure.

Key Inputs Used in the Epoxy Calculator

This calculator uses real-world epoxy standards and covers most common use cases.

1. Surface Length and Width

You enter the surface size in inches. The calculator converts this into square inches and square feet automatically.

Example:
A table that is 48 inches long and 24 inches wide.

2. Application Type

The calculator includes preset thickness values based on how epoxy is normally used.

• Seal Coat / Brush On (Thin)
  Used to seal wood or porous surfaces
  Default thickness: 10 mils
• Table Top / Flood Coat
  Common for countertops and tables
  Default thickness: 1/8 inch
• Deep Pour / Casting
  Used for river tables and molds
  Default thickness: 1 inch
• Custom Thickness
  Lets you enter your own value

These presets reduce mistakes and speed things up.

3. Coating Thickness Units

You can enter thickness in:

• Inches
• Millimeters (mm)
• Mils (1 mil = 0.001 inch)

The calculator converts everything into inches internally so the math stays accurate.

4. Mixing Ratio

Different epoxy systems use different ratios. This calculator supports:

• 1:1
• 2:1
• 3:1
• 4:1

Once the total volume is known, the calculator splits it correctly into resin and hardener.

Example:
If the total volume is 1 gallon at a 2:1 ratio:

• Resin (Part A): 0.67 gallons
• Hardener (Part B): 0.33 gallons

5. Waste and Porosity Factor

No project is perfectly efficient. Some epoxy stays in the cup, some soaks into wood, and some is lost during spreading.

The calculator adds a waste percentage, usually between 5% and 10%.

• Smooth, sealed surfaces: 5%
• Raw wood or concrete: 8–10%

This small buffer prevents shortages.

How the Epoxy Calculator Works (Behind the Scenes)

The calculator follows a standard epoxy formula:

1. Area Calculation
   Length × Width = Surface area (square inches)
2. Thickness Conversion
   All units are converted to inches
3. Volume Calculation
   Area × Thickness = Cubic inches of epoxy
4. Unit Conversion
   231 cubic inches = 1 gallon
5. Waste Adjustment
   Total volume × (1 + waste percentage)
6. Mix Ratio Split
   Total volume is divided into resin and hardener

This is the same method used by epoxy manufacturers.

What Results the Calculator Shows

Once you click Calculate Volume, you see:

• Total mixed volume
  Shown in gallons and liters (or milliliters for small amounts)
• Part A (Resin)
  Displayed in gallons or fluid ounces
• Part B (Hardener)
  Displayed in gallons or fluid ounces
• Approximate coverage area
  Shown in square feet

Small quantities are automatically shown in fluid ounces or milliliters to make measuring easier.

Practical Example

Let’s say you are coating a tabletop:

• Length: 48 inches
• Width: 24 inches
• Thickness: 1/8 inch
• Mixing ratio: 1:1
• Waste factor: 5%

The calculator will show:

• Total epoxy needed in gallons and liters
• Exact resin and hardener amounts
• Coverage confirmation in square feet

This removes guesswork and keeps your mix accurate.

Tips for Better Epoxy Results

• Always measure resin and hardener by volume, not weight, unless the manufacturer says otherwise
• Seal porous surfaces before flood coating
• Mix slowly and thoroughly to avoid bubbles
• Only mix what you can use within the pot life

The calculator helps with quantity, but good technique still matters.