Small Batch Resin Mixing Calculator
Calculate exact Part A and Part B measurements for any resin brand ratio.
Supports 1:1, 2:1, 3:1 and custom ratios — optimised for small craft batches.
For large batches or a full ratio reference guide, see the Resin Ratio
Calculator.
No sign-ups. Instant results.
💡 Tip: Always use a digital scale for measuring by weight. It's more accurate than volume measurements.
Example calculation
Let's calculate measurements for a small jewelry project using ArtResin (1:1 ratio):
| Parameter | Value |
|---|---|
| Total resin needed | 100 grams |
| Resin ratio | 1:1 (equal parts) |
| Add 10% buffer | Yes |
| Part A (Resin) | 55 grams |
| Part B (Hardener) | 55 grams |
| Total mixed | 110 grams (with buffer) |
The 10% buffer (10 grams extra) accounts for waste and ensures you don't run short mid-pour.
Resin mixing ratios by brand: 1:1, 2:1 and more
| Resin Brand | Ratio (A:B) | Type |
|---|---|---|
| ArtResin | 1:1 | Craft/Art |
| Let's Resin | 1:1 | Craft/Jewelry |
| Dr Crafty | 1:1 | Craft/Art |
| Stone Coat | 1:1 | Table Top |
| TotalBoat ThickSet | 2:1 | Deep Pour |
| Famowood Glaze Coat | 1:1 | Table Top |
| MAS Epoxies (Table Top) | 2:1 | Table Top / Deep Pour |
| WiseBond Deep Pour | 2:1 | Deep Pour |
| Promise Epoxy | 2:1 | Table Top |
⚠️ Always check your specific product label. Ratios can vary even within the same brand's product line. For a full brand ratio guide including weight vs volume differences, see the Resin Ratio Calculator.
What do resin mixing ratios mean? 1:1, 2:1 and 3:1 explained
A resin mixing ratio tells you how many parts of Part A (resin) to combine with how many parts of Part B (hardener). The ratio must be followed exactly — it's not a preference, it's a chemical requirement. Use the calculator above to get the exact weights for your batch size and ratio.
1:1 ratio (equal parts)
The most common ratio for craft resins. For every gram of Part A, you add exactly one gram of Part B. A 1:1 ratio is the easiest to work with because the split is always 50/50 regardless of batch size. Used by ArtResin, Dr Crafty, Let's Resin, Stone Coat, and most beginner-friendly epoxy kits.
2:1 ratio (two parts resin, one part hardener)
A 2:1 ratio means Part A makes up two-thirds of the total batch and Part B makes up one-third. This is common for deep pour resins and some table top formulas. The larger proportion of resin creates a slower, lower-heat cure — important for thick pours where internal heat buildup is a risk. Used by TotalBoat ThickSet, WiseBond Deep Pour, MAS Epoxies, and Promise Epoxy.
3:1 ratio (three parts resin, one part hardener)
Part A is 75% of the total batch, Part B is 25%. Less common in craft resins but found in some industrial and coating formulas. Requires careful measurement — the smaller Part B proportion means a small error has a larger percentage impact on the ratio than it would with a 1:1 mix.
Resin mix ratio calculator: worked examples by ratio
The table below shows exact Part A and Part B amounts for common batch sizes at each ratio. All values are by weight (grams). For other amounts, use the calculator above.
| Total Batch | 1:1 — Part A / Part B | 2:1 — Part A / Part B | 3:1 — Part A / Part B |
|---|---|---|---|
| 30g | 15g / 15g | 20g / 10g | 22.5g / 7.5g |
| 50g | 25g / 25g | 33.3g / 16.7g | 37.5g / 12.5g |
| 100g | 50g / 50g | 66.7g / 33.3g | 75g / 25g |
| 150g | 75g / 75g | 100g / 50g | 112.5g / 37.5g |
| 200g | 100g / 100g | 133.3g / 66.7g | 150g / 50g |
| 300g | 150g / 150g | 200g / 100g | 225g / 75g |
| 500g | 250g / 250g | 333.3g / 166.7g | 375g / 125g |
💡 Values are by weight. For non-standard batch sizes or custom ratios, use the calculator above. Always verify your brand's ratio on the product label — ratios can differ between a brand's casting and table top formulas even when sold under the same name.
Volume vs weight: why the ratio unit matters
Most resin brands specify their ratio by volume, but you should always measure by weight. For a 2:1 ratio specified by volume, measuring by weight gives nearly identical results for most epoxy resins (density ~1.1 g/ml) and is significantly more accurate than using measuring cups. The worked examples above use weight throughout. If your brand specifies ratio by weight specifically, the calculator handles both — select grams and enter your batch size.
Need the full volume vs weight ratio explainer, or working with batches over 500ml? See the Resin Ratio Calculator — covers weight ratio differences for 2:1 brands and includes reference tables for large batch sizes.
Accurate resin mixing tips
⚖️ Use a digital scale
Measure by weight, not volume. Get a scale that measures to 0.1g accuracy for small batches under 100g.
🧪 Mix thoroughly
Stir for 3-5 minutes, scraping sides and bottom. Unmixed resin will have soft spots that never cure.
🕐 Work within pot time
Most resins have 30-45 minute pot time. Mix small batches if you need more working time.
🌡️ Room temperature matters
Resin works best at 70-75°F (21-24°C). Cold resin is thick and hard to mix. See the resin temperature guide for working time adjustments by temperature.
💡 Need supplies? Shop: Resin Kits • Digital Scales • Mixing Cups
Resin ratio and mixing FAQs
What is the mixing ratio for most resin brands?
Most craft resins use a 1:1 ratio by volume or weight (equal parts A and B). However, some brands use 2:1, 3:1, or 4:1 ratios. Always check your specific resin brand's instructions. Popular brands like ArtResin use 1:1, while some deep pour resins use 2:1.
Should I measure resin by weight or volume?
Always measure by weight using a digital scale for accuracy. Volume measurements can be off by 10-15% due to air bubbles and density variations. Weight is the most reliable method and what professional resin crafters use.
How much extra resin should I mix?
Mix 10-15% more than your calculated amount. This accounts for waste in mixing cups, popping air bubbles, and resin that sticks to stirring tools. Use the buffer option in this calculator to automatically add 10% extra.
What happens if I get the ratio wrong?
Incorrect ratios result in resin that never fully cures or stays tacky forever. The chemical reaction between Part A and Part B requires precise ratios. Even being off by 5-10% can ruin your project. Always use a digital scale and follow your brand's exact ratio.
Can I mix different amounts of Part A and Part B if I run out?
No, never alter the ratio specified by your resin brand. If you run out of Part A or B, you must purchase more of that specific component. Changing the ratio will cause the resin to fail. Unopened resin components typically last 1-2 years when stored properly.
Can I mix resin in any container?
Use clean, disposable plastic or silicone mixing cups with smooth interiors. Avoid paper cups (resin can soak through), foam cups (resin melts them), or cups with ridges that make thorough mixing difficult. Graduated measuring cups help you see your amounts clearly.
How long do I need to stir resin?
Stir thoroughly for at least 3 minutes, scraping the sides and bottom of your cup. Inadequate mixing is one of the most common causes of resin failure. Set a timer—most people don't stir long enough. For larger batches (over 200g), stir for 5 minutes.
If your resin comes out tacky or soft, the most common cause is measuring by volume cups instead of a scale. The Sticky Resin Guide covers all causes and whether the batch can be saved.
What does a 2:1 ratio mean for resin mixing?
A 2:1 ratio means you use 2 parts Part A (resin) for every 1 part Part B (hardener) — by weight or by volume depending on your brand's instructions. In practice: for a 90g batch, you measure 60g Part A and 30g Part B. For a 150g batch: 100g Part A and 50g Part B. The 2:1 split gives Part A a 66.7% share and Part B a 33.3% share of the total. See the mix ratio reference table above for common batch sizes at 2:1.
How do I calculate a 2:1 or 3:1 resin ratio by weight?
For a 2:1 ratio: divide your total batch weight by 3, then multiply by 2 for Part A and by 1 for Part B. Example: 120g total ÷ 3 = 40g. Part A = 80g, Part B = 40g. For a 3:1 ratio: divide total by 4, multiply by 3 for Part A and by 1 for Part B. Example: 120g total ÷ 4 = 30g. Part A = 90g, Part B = 30g. Or skip the math — enter your total amount and select your ratio in the calculator above for instant results.
Which resin brands use 2:1 and which use 1:1?
1:1 ratio brands (equal parts): ArtResin, Dr Crafty, Let's Resin, Stone Coat, Alumilite Amazing Clear Cast, Teexpert, and most beginner craft resin kits. 2:1 ratio brands (2 parts resin, 1 part hardener): TotalBoat ThickSet, WiseBond Deep Pour, MAS Epoxies, Promise Epoxy, and SuperClear Epoxy. Always confirm on your product label — some brands use 1:1 for their table top formula and 2:1 for their deep pour formula.
What happens if I accidentally use the wrong ratio?
The result depends on how far off you are. Being 5% off on a 1:1 mix (e.g. 52g + 48g instead of 50g + 50g) will usually cure with minor soft spots. Being 20%+ off — or using a 1:1 ratio when your resin requires 2:1 — will likely result in resin that stays permanently tacky, never reaches full hardness, or fails entirely. There is no fix once resin is poured incorrectly — the batch must be discarded. Use a digital scale and double-check your brand's ratio before every mix.