Epoxy Mix Ratio 1:1
A 1:1 epoxy ratio means equal volumes of resin and hardener — the most common ratio for tabletop, countertop, and art epoxies. This guide explains what it means in practice, how to measure it accurately, and gives you a batch-size reference table for any project.
Know your ratio — now calculate exactly how much you need for your project.
Use the Free Calculator →What 1:1 Ratio Means
A 1:1 mix ratio means you combine equal volumes of Part A (resin) and Part B (hardener). For every unit of resin, you add the same unit of hardener — regardless of whether you measure in fluid ounces, millilitres, cups, or any other volume unit.
Total batch = Resin + Hardener
Example: 10 fl oz resin + 10 fl oz hardener = 20 fl oz mixed
The 1:1 ratio is by volume unless your product label explicitly states "by weight." Volume is the standard for most hobby, art, and tabletop epoxy brands. If unsure, check the label — mixing by weight when the ratio is by volume (or vice versa) will cause curing failure.
Volume vs. weight: Resin and hardener have different densities, so a 1:1 volume ratio is NOT a 1:1 weight ratio. Most 1:1 epoxies are 1:1 by volume. Using a scale instead of a graduated cup will give incorrect proportions unless the label specifies a weight ratio.
How to Calculate Batch Sizes (1:1)
With a 1:1 ratio, each component is always exactly half the total volume. The formula is simple:
Hardener = Total needed ÷ 2
Example: Need 24 fl oz total → 12 fl oz resin + 12 fl oz hardener
1:1 Batch Size Reference Table
| Total Mixed (fl oz) | Part A Resin | Part B Hardener | Total Mixed (mL) |
|---|---|---|---|
| 4 fl oz | 2 fl oz | 2 fl oz | ~118 mL |
| 8 fl oz | 4 fl oz | 4 fl oz | ~237 mL |
| 16 fl oz (1 pt) | 8 fl oz | 8 fl oz | ~473 mL |
| 24 fl oz | 12 fl oz | 12 fl oz | ~710 mL |
| 32 fl oz (1 qt) | 16 fl oz | 16 fl oz | ~946 mL |
| 48 fl oz | 24 fl oz | 24 fl oz | ~1,420 mL |
| 64 fl oz (½ gal) | 32 fl oz | 32 fl oz | ~1,893 mL |
| 128 fl oz (1 gal) | 64 fl oz | 64 fl oz | ~3,785 mL |
Always add 10% extra to your calculated total before looking up batch size — mixing cups retain some product and drips occur at the edge of the pour.
Common Products That Use 1:1
Tabletop & Countertop Epoxies
Most clear tabletop and countertop epoxies use 1:1 by volume. These systems are designed for thin flood coats (1/8 in or less) and are self-leveling with relatively short pot times (30–45 min).
- TotalBoat Table Top Epoxy — 1:1 by volume
- ProMarine Supplies Table Top — 1:1 by volume
- Stone Coat Countertop — 1:1 by volume
- Most art resin brands (ArtResin, EasyBond, etc.) — 1:1 by volume
Casting Resins
Many deep-pour casting resins also use 1:1, though some switch to 2:1. Always confirm with the product data sheet — deep-pour resins designed for thick pours need precise mixing more than tabletop systems because incorrect ratios generate excess heat.
- Deep pour casting resins: often 1:1 or 2:1 — check label
- Crystal clear jewelry resins: usually 1:1 by volume
- UV resin: single component, no mixing required
How to Measure 1:1 Accurately
- Use a graduated mixing cup. Plastic graduated cups (available at hardware and craft stores) show volume markings directly. Pour Part A to the desired line, then pour Part B to double that line.
- Measure each component separately if using large volumes. For batches over 32 fl oz, measure into separate containers first, then combine into a large mixing bucket.
- Scrape the sides of the measuring cup. Product clings to container walls — use a silicone spatula to scrape everything into the mixing vessel.
- Mix thoroughly for the time specified. Most 1:1 epoxies require 3–5 minutes of thorough stirring, scraping the sides and bottom, before pouring.
- Do not aerate. Stir slowly and deliberately — rapid mixing introduces air bubbles that require torching to remove.
Do not eyeball it. A 10% off ratio (9:11 instead of 10:10) can cause permanent soft spots, cloudiness, or total curing failure. Always use a calibrated measuring cup or scale (if ratio is by weight).
What Happens if the 1:1 Ratio Is Wrong
Epoxy cures through a chemical reaction between resin and hardener. The ratio must be correct for all molecules to find their reaction partners:
- Too much resin (not enough hardener): The epoxy stays soft, tacky, or rubbery. Unreacted resin remains liquid indefinitely — it won't cure further.
- Too much hardener (not enough resin): The epoxy may cure brittle or cloudy. Excess hardener can leach to the surface as a white haze or amine blush.
- More than 10% off ratio: High risk of complete curing failure. The pour must be sanded off and redone.
Frequently Asked Questions
What does 1:1 epoxy ratio mean?
Equal volumes of resin and hardener. For every unit of Part A, you add the same unit of Part B. The total mixed volume is the sum of both. Most tabletop and art epoxy brands use this ratio.
Is 1:1 epoxy ratio by weight or volume?
Almost always by volume unless the label says otherwise. Resin and hardener have different densities, so a 1:1 volume ratio gives different weights for each component. Use a graduated measuring cup, not a kitchen scale, unless weight mixing is specified.
How much hardener do I add to 16 oz of resin (1:1)?
16 fl oz of hardener — equal to the resin amount. Total mixed batch = 32 fl oz (1 quart). Always add 10% to your target quantity before mixing to account for waste in the mixing cup.
Can I mix a smaller or larger batch with 1:1 ratio?
Yes — the ratio stays 1:1 regardless of batch size. A 2 fl oz test batch uses 1 fl oz resin + 1 fl oz hardener. A 128 fl oz batch uses 64 fl oz resin + 64 fl oz hardener. The proportion never changes.