# How to calculate power loss between radio and antenna

I have a 5W HT that only kicks out about 1W by the time it hits my antenna (which I understand is the norm). How do I go about calculating power loss in various equipment?

• Hmm? What equipment? Nothing should be causing a 6dB loss unless the HT is running through 50 feet of RG-58 or some such assembly before it gets to the antenna. Oct 28 '13 at 16:58
• It's a Baofeng handheld.
– Dan
Oct 28 '13 at 18:34
• How do you know that only 1W is hitting the antenna? Is this antenna mounted on the handheld, or through a feedline? What kind, and how long? Feb 26 '14 at 22:20
• @PhilFrost through an adapter and then through a 20 ft 10 ft feedline which is way too long. But I don't know the actual loss. I was hoping for a formula to calculate it, the current answer does a good job.
– Dan
Feb 26 '14 at 22:35

Finally, to calculate your actual radiated power, you can simply add up all these values. Every 3dB equates to cutting your signal in half, and 10dB equates to one tenth of your original power getting out. You would compute the actual power by multiplying your transmitter's power by $10^{(-\mathrm{loss~}(\mathrm{in~dB})/10)}$