How to do a Bicep Curl
The bicep curl is an elbow-flexion exercise that isolates the biceps. Good form means the elbows stay pinned to your sides while only the forearms move, with a controlled lower on every rep. CalmArms grades each curl A–F in real time and counts your reps hands-free.
Muscles: Biceps · Forearms · Brachialis
Demonstration: Standard Bicep Curl
How to do it with clean form
- 1
Stand tall with a weight in each hand, arms extended, palms facing forward.
- 2
Curl the weight up by bending only at the elbow — keep your upper arms still.
- 3
Squeeze at the top without swinging your shoulders or leaning back.
- 4
Lower under control all the way to a full stretch before the next rep.
Common bicep curl mistakes CalmArms catches
Swinging the torso or using momentum to move the weight.
Elbows drifting forward or flaring out from your sides.
Cutting the range short — not reaching full extension at the bottom.
Racing the lowering phase instead of controlling it.
How CalmArms grades the bicep curl
CalmArms weights elbow angle and range of motion heavily on the curl, and docks stability points for body English — so a strict, controlled curl earns its A while a swung rep does not.
Variations graded
Grade your bicep curl on your next set.
Prop your phone and lift. CalmArms counts every rep and grades your form A–F, hands-free — on-device, no video uploaded.