title: Storage size of NFC Tag
body: <p>I have an NXP NTAG216 and I want to know the storage size of the tag. From the specification I read that the size of the data area is in <code>Block 3</code> <code>Byte 2</code> which is <code>7F</code> in my case which is <code>127</code> in decimal and times <code>8 Bytes</code> it is <code>1016 Bytes</code>. From the NXP website It states that the tag only has <code>924 Bytes</code> <a href="https://www.nxp.com/products/rfid-nfc/nfc-hf/ntag/ntag-for-tags-labels/ntag-213-215-216-nfc-forum-type-2-tag-compliant-ic-with-144-504-888-bytes-user-memory:NTAG213_215_216" rel="nofollow noreferrer">NXP NTAG 213/215/216</a>.</p>
  <pre><code>[0]    04 : 91 : 52 : 4F
  [1]    9A : 9A : 40 : 80 
  [2]    C0 : 48 : 00 : 00 
  [3]    E1 : 10 : 7F : 00 
  </code></pre>
  <p>Similar with a NXP NTAG215 which has <code>3E</code> in decimal <code>62</code> times <code>8 Bytes</code> is <code>496 Bytes</code> where the website says <code>540 Bytes</code>.</p>
  <pre><code>[0]    04 : 34 : DB : 63 
  [1]    6A : 83 : 5C : 81 
  [2]    34 : 48 : 00 : 00 
  [3]    E1 : 10 : 3E : 00 
  </code></pre>
  <p>Can someone explain to me how this number is calculated?</p>