MicroSD Card Size and Speed Calculator
Work out the card capacity and write speed you need for video recording or a console, and read what the speed marks mean. Free, private and instant.
Where to buy
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How to use the MicroSD Card Size and Speed Calculator
- Enter your values in the fields above.
- The result updates automatically as you type.
- Copy or note the figures you need.
About this tool
Choose what you are recording or using the card for, and how long you want to record. The calculator turns the video bitrate into the write speed (MB/s) and the gigabytes you need, with a safety margin, and shows which speed class marks to look for: U1, U3, V30, V60, V90, A1 and A2. It cannot tell you your device's maximum supported capacity or card type, so check the device's manual before buying.
MicroSD Card Size and Speed Calculator is part of ToolStack Hub's Calculators. It runs entirely in your browser, which keeps your data private and makes results instant. There is nothing to install, no account to create and no usage limit.
Frequently asked questions
What do U3, V30 and A2 mean?
U3 and V30 both guarantee at least 30 MB/s sustained writing, which suits 4K video. A1 and A2 describe how quickly a card handles small random reads and writes, important for apps and games.
What size card do I need?
It depends on bitrate and recording time. At 100 Mbps, 4K video fills about 45 GB an hour, so a 128 GB card holds roughly two and a half hours.
Is the MicroSD Card Size and Speed Calculator free?
Yes. MicroSD Card Size and Speed Calculator is completely free with no sign-up, limits or watermarks.
Is my data private when I use the MicroSD Card Size and Speed Calculator?
Yes. It runs in your browser, so your input is not uploaded to our servers.
Does it work on mobile?
Yes. ToolStack Hub tools work on phones, tablets and desktop browsers.
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