NTAG213
144 B user memory
111 B remaining
Payload input
What will the tag store?
Detected: URL → URI record
33 characters
The calculator trims whitespace around URL input and applies a standard http(s) prefix abbreviation.
Modeled total
33bytes
NDEF record + Type 2 TLV
Exact NDEF size for URL and text records; other record types differ
Chip fit
Fits
NTAG215
504 B user memory
471 B remaining
NTAG216
888 B user memory
855 B remaining
Recommendation
NTAG213 is the smallest calculated fit.
NTAG213 is the smallest published capacity that fits the 33-byte record, with 111 bytes to spare.
Guide rule of thumb: URL under 50 characters → NTAG213 (144 bytes) with room to spare
Byte breakdown
- Input content (UTF-8)
- 33 B
- URI identifier code
- 1 B
- “https://” stored as a 1-byte code (0x04): 8 B replaced by 1 B (7 B saved).
- Stored URI remainder
- 25 B
- NDEF payload
- 26 B
- NDEF record header
- 4 B
- 1 B flags + 1 B type length + 1 B payload length + 1 B type “U”.
- Complete NDEF record
- 30 B
- Type 2 TLV wrapper
- 3 B
- 1 B 0x03 type + 1 B length + 1 B 0xFE terminator.
Total bytes needed33 B
Calculation model
What the estimate counts
One NDEF record is placed inside an NFC Forum Type 2 Tag TLV. The calculation below models the fields listed here.
URI prefix compression
Standard http and https prefixes use one identifier byte, so the repeated prefix text does not have to be stored in full.
NDEF record overhead
The estimate includes the payload, record flags, type, type length and the short or long payload-length field.
Type 2 TLV wrapper
The estimate adds the NDEF TLV type, its one- or three-byte length field, and a terminator byte.
Need the decision rules and encoding cautions? Read the full memory and payload guide.