The On Balance CK-20 is a compact tabletop scale that delivers 0.001g precision across a 20g capacity — proper microdosing accuracy without the lab-bench footprint. At 8.4 × 10.5 × 3.6cm it fits in a drawer, a pocket, or next to your grinder, and the two-button interface is genuinely idiot-proof.
Why the On Balance CK-20 belongs on your bench
If you're weighing anything under a gram, kitchen scales lie to you. They round, they drift, they bottom out at 0.1g — and 0.1g of a 0.001g-sensitive substance is the difference between a measured dose and a guess. The CK-20 reads to one thousandth of a gram, which is the resolution you actually need for microdosing herbs, weighing concentrates, or portioning out extracts.
On Balance has been making these things since the early 2000s and the CK-20 is one of their tidiest tabletop units. The white backlit LCD is readable in dim light (handy if you're working under a desk lamp), the overload protection means you won't fry the load cell by accident, and the included tweezers let you nudge tiny amounts on and off the pan without spillage. It's not waterproof, it's not Bluetooth, it's not trying to be a lab balance — it's a precise pocket-friendly scale that does one job well.
Honest limitation: the 20g ceiling is low. If you're weighing out 14g of dry flower for a jar, this isn't the scale — grab the On Balance Myco (100g × 0.01g) instead. The CK-20 is built for the small end of the spectrum, where 0.001g actually matters.
CK-20 vs the rest of the On Balance line-up
The CK-20 sits in the milligram-precision bracket alongside the MTT-100. Here's how it stacks against the closest siblings we carry, so you can pick once and pick right.
| Model | Capacity | Resolution | Best for |
|---|---|---|---|
| CK-20 | 20g | 0.001g | Microdoses, extracts, tiny portions |
| MTT-100 | 100g | 0.005g | Concentrates, resins, mid-range precision |
| Myco | 100g | 0.01g | Dry herb, daily flower weighing |
| Envy Mini | 500g | 0.01g | Larger batches, bulk botanicals |
Specifications at a glance
Everything you need to know on one screen — these are the manufacturer figures from On Balance, not estimates.
| Brand | On Balance |
| Model | CK-20 |
| Maximum capacity | 20g |
| Readability | 0.001g |
| Dimensions | 8.4 × 10.5 × 3.6cm |
| Display | White backlit LCD |
| Power | 2× AAA batteries |
| Weighing units | g, oz, ozt, dwt, ct, gn |
| Overload protection | Yes |
| Included | Tweezers, batteries |
| Controls | Two-button interface |
How to use the CK-20
Two buttons, six units, one tare function. You'll have it down in under a minute.
- Place the scale on a flat, level surface — no wobbly tables, no tablecloth, no draughts from an open window. Air movement actually registers at 0.001g.
- Press the power button. Wait for the display to settle on 0.000g.
- Cycle the unit button to select your preferred weighing unit (g, oz, ozt, dwt, ct, or gn).
- Place an empty weighing tray or paper on the pan, then press tare to zero out the container weight.
- Use the included tweezers to add your substance in small amounts until you hit the target weight.
- Power off when done. The scale auto-shuts after a period of inactivity to preserve the batteries.
From our counter: the calibration question
The number one issue customers bring back with milligram scales isn't a fault — it's a flat surface. We've watched people weigh on a glass kitchen table next to a fridge that vibrates every 30 seconds and wonder why their reading drifts. A small wooden cutting board on a solid worktop solves 90% of "my scale is broken" complaints. Calibration weights are sold separately if you want to verify accuracy periodically, and we'd recommend it for anyone weighing doses regularly.
Complete your setup: pair the CK-20 with a set of calibration weights to verify accuracy over time, and grab a small set of weighing trays or gel caps if you're portioning out powders. For larger quantities above the 20g ceiling, the On Balance Myco handles up to 100g at 0.01g resolution.
Frequently Asked Questions
How accurate is the On Balance CK-20 really?
The CK-20 reads to 0.001g across its 20g capacity — that's milligram precision, the same bracket used in pharmacy pill-counting scales. Accuracy holds best on a flat, stable surface away from air movement and vibration. Verify with calibration weights periodically for consistent results.
Can I weigh more than 20g on it?
No — 20g is the hard ceiling and the built-in overload protection will flag anything heavier to prevent damage to the load cell. For 100g capacity at 0.01g resolution, the On Balance Myco is the closest sibling. For 500g, look at the Envy Mini.
What units does the CK-20 measure in?
Six units: grams (g), ounces (oz), troy ounces (ozt), pennyweight (dwt), carats (ct), and grains (gn). Cycle through with the unit button. Grams and carats are the most common for botanicals and concentrates.
Do I need calibration weights?
Not to start — the CK-20 arrives factory-calibrated. For long-term accuracy, especially if you're weighing precise doses regularly, a small calibration weight set lets you verify and recalibrate. Sold separately on the smartshop.
How long do the batteries last?
The CK-20 runs on two standard AAA batteries (included). Real-world use gives you months of casual weighing before a swap. Auto shut-off after inactivity extends battery life — leave the scale on and it'll turn itself off.
Is the CK-20 good for weighing tablets or microdoses?
Yes — 0.001g resolution is well-suited to weighing small portions, capsule contents, or microdose amounts. Remember that tablet filler adds weight, so a 3.5mg active dose will weigh more than 3.5mg total. Use the tare function with a weighing tray for clean readings.
Last updated: April 2026
