The feathers shall be measured from the tip to the top of the base and each shuttlecock shall be of the same length. This length can be between 62mm and 70mm. The shuttlecock shall weigh between 4.74 to 5.50 grams.
shuttlecocks are usually graded according to speed. If you have reached a certain level and can hit from baseline to baseline, use standard speed shuttlecockcocks. If your strength is not there yet, you can use shuttlecockcocks of a slightly faster speed.
You will enjoy the game more if you can send the shuttlecocks to the baseline.
The speed at which the shuttlecock travels is also affected by the weather, altitude and temperature. When it's hot, the shuttlecock will fly faster. When it's cold, the shuttlecock will move slower. If you are playing in an air-conditioned hall, use a slightly faster shuttlecock. If you're playing at high altitude, use a slower speed shuttlecock.
To test the speed of a shuttlecock, use a full underhand stroke which makes contact with the shuttlecock over the back boundary line. You shall hit the shuttlecock at an upward angle and in a direction parallel to the side lines.
A shuttlecock of correct speed will land not less than 530 mm and not more than 990mm short of the Badminton Court back boundary line as in the diagram below.
If you find the shuttlecock is too fast or too slow but you don't have shuttlecocks of different speed, you can try tipping the shuttlecock. Tipping the feathers of the shuttlecocks outward will slow it down. Tipping the feathers of the shuttlecocks inward will speed it up.