NFC Tag Size Calculator
Check whether your content fits on an NFC tag. Select your tag type, choose the content type, enter your data, and see exactly how many bytes are needed versus how many are available. Supports NTAG213, NTAG215, NTAG216, NTAG424, and MIFARE Classic 1K.
An NFC tag holds between 144 and 888 bytes of user memory depending on its chip: NTAG213 144 bytes, NTAG424 DNA 416, NTAG215 504, MIFARE Classic 1K about 716 usable, and NTAG216 888. This free browser-based calculator subtracts the NDEF record overhead and tells you whether your URL, vCard or WiFi record actually fits. Updated 2026-09-09.
How the NFC Tag Size Calculator Works
Pick your tag type, choose the kind of record you want to write — URL, plain text, vCard or WiFi credentials — and paste in your content. The calculator counts the bytes of your payload, adds the NDEF header overhead for that record type, and compares the total against the tag's user memory, so you find out before you buy a reel of 100 tags rather than after. Everything runs in your browser and nothing is sent to a server.
Understanding NFC Tag Types and Storage Capacity
NFC (Near Field Communication) tags are small, passive electronic chips that store data and transmit it wirelessly when tapped by an NFC-enabled device. Each tag type has a specific memory capacity that determines how much data it can hold. Understanding these capacities is crucial when planning NFC projects, whether you are creating digital business cards, smart product labels, access control systems, or interactive marketing materials.
The most common NFC tag families are the NXP NTAG series and the MIFARE Classic series. Each has different storage capacities, security features, and price points. Choosing the right tag for your project depends on how much data you need to store, what security level you require, and your budget constraints. This calculator helps you determine whether your content will fit on your chosen tag type before you purchase or program any tags.
NFC Tag Types Explained
NTAG213 (144 bytes)
The NTAG213 is the smallest and most affordable tag in the NTAG series. With 144 bytes of user-writable memory, it is ideal for short URLs, phone numbers, and simple text records. It is the most commonly used tag for URL-based NFC applications like smart posters, product packaging, and marketing materials where you simply want to direct users to a website. Its small memory makes it the most cost-effective option when you do not need to store large amounts of data.
NTAG215 (504 bytes)
The NTAG215 offers 504 bytes of storage, making it suitable for vCards, longer URLs, and WiFi network credentials. It is the most popular choice for digital business cards and NFC-enabled contact sharing because it provides enough space for a full vCard with name, phone, email, company, title, and website. The NTAG215 is also the tag type used by Nintendo Amiibo figures, which has made it widely available and affordable.
NTAG216 (888 bytes)
With 888 bytes of storage, the NTAG216 is the largest tag in the standard NTAG series. It can store extensive vCards with multiple phone numbers and addresses, long text messages, or complex NDEF records. This tag is recommended when you need to encode detailed contact information, multiple URLs, or structured data that exceeds what the NTAG215 can hold.
NTAG424 DNA (416 bytes)
The NTAG424 DNA is a security-focused tag with 416 bytes of storage and advanced authentication features. It supports AES-128 encryption, secure dynamic messaging, and tamper detection. This tag is primarily used in brand protection, anti-counterfeiting, and access control applications where data integrity and authentication are critical. While it has less raw storage than the NTAG216, its security features make it the premium choice for sensitive applications.
MIFARE Classic 1K (716 bytes usable)
The MIFARE Classic 1K is an older but widely deployed tag type with approximately 716 bytes of usable storage across its 16 sectors. It was originally designed for transit cards and access control systems. While it supports NDEF formatting for NFC data exchange, its security has been compromised and it is not recommended for new security-sensitive applications. It remains common in legacy systems and budget-friendly projects.
NDEF Format and Data Overhead
NFC tags store data using the NDEF (NFC Data Exchange Format) standard. Each NDEF record includes header bytes that specify the record type, payload length, and other metadata. This overhead reduces the usable space for your actual content. URL records have approximately 5 bytes of overhead (type byte, length bytes, and URI identifier code). Text records add about 7 bytes for language code and encoding information. vCard records require around 10 bytes for the MIME type declaration and record structure. Understanding this overhead is essential for accurate capacity planning.
How Many Characters Fit on an NFC Tag?
Datasheets quote bytes, but people write URLs, so here is the same capacity in characters. One plain ASCII character is one byte, so after subtracting NDEF overhead an NTAG213 fits roughly 132 characters of URL, an NTAG424 DNA about 404, an NTAG215 about 492, a MIFARE Classic 1K about 704, and an NTAG216 about 876. Two things shrink that further. First, the URI record type stores a common prefix as a single byte, so writing https:// at the start costs one byte instead of eight — a real saving on the smallest tags. Second, any non-ASCII character is UTF-8 encoded and takes two to four bytes, so an emoji or an accented character can quietly cost four times what you expected; a 100-character text record in Arabic or Japanese will not fit on an NTAG213 even though 100 is well under 144. The record layout and the URI prefix table are defined by the NDEF and RTD specifications published by the NFC Forum, the body that standardises the format all these tags use. If you are close to the limit, shorten the URL rather than upgrading the tag — a link shortener usually saves more bytes than the next chip size buys. Updated 2026-09-09.
Common NFC Use Cases
NFC tags are used across countless applications: digital business cards for networking, smart product labels for authentication, WiFi sharing in hotels and restaurants, event check-in and badge scanning, interactive museum exhibits, contactless payment triggers, smart home automation, pet identification tags, and much more. Each use case has different storage requirements, and this calculator helps you match your content to the appropriate tag type.
Frequently Asked Questions
How much data can an NFC tag hold?
It depends on the tag type. NTAG213 holds 144 bytes, NTAG215 holds 504 bytes, NTAG216 holds 888 bytes, NTAG424 DNA holds 416 bytes, and MIFARE Classic 1K holds approximately 716 usable bytes. The actual usable space is slightly less due to NDEF record headers and overhead.
What is NDEF overhead?
NDEF (NFC Data Exchange Format) is the standard for storing data on NFC tags. Each NDEF record includes header bytes for record type, payload length, and flags. This overhead typically ranges from 5 to 10 bytes depending on the content type. URLs have about 5 bytes overhead, text records about 7 bytes, and vCards about 10 bytes.
Which NFC tag should I use for a digital business card?
NTAG215 (504 bytes) is the most popular choice for digital business cards. It provides enough space for a full vCard with name, phone, email, company, title, and website URL. If you need to include additional details like multiple phone numbers or a physical address, consider the NTAG216 (888 bytes).
Can I rewrite data on an NFC tag?
Yes, most NFC tags are rewritable by default. You can change the data as many times as you want using NFC writing apps. However, tags can be permanently locked to prevent further changes, which is useful for security applications. The NTAG series supports a one-time lock feature that makes the tag read-only permanently.
Do all phones support NFC?
Most modern smartphones support NFC. All iPhones from iPhone 7 onward support NFC reading, with iPhone XS and later supporting background NFC reading without opening an app. Android devices have supported NFC since version 4.0 (2011), and virtually all Android phones sold since 2015 include NFC capability.
How many characters fit on an NFC tag?
For plain ASCII, one character is one byte, so after NDEF overhead an NTAG213 fits about 132 characters of URL, an NTAG424 DNA about 404, an NTAG215 about 492, a MIFARE Classic 1K about 704, and an NTAG216 about 876. Non-ASCII characters are UTF-8 encoded and cost two to four bytes each, so an emoji or an accented letter uses up to four times the space.
Does https:// count against the NFC tag capacity?
Barely. The NDEF URI record type stores common prefixes as a single identifier byte, so https://www. and https:// each cost one byte instead of eight or twelve. That is why a URL record has only about 5 bytes of total overhead. If you are near the limit on an NTAG213, shortening the path saves more space than switching to a bigger chip.