60 RGBW LEDs per Meter. For true white color rendition with an LED strip, you need to include a separate white LED from the other red, green, and blue LEDs. Like this one, using the SK6812 RGBW LED.
As beautiful as regular RGB are, for proper color rendition a white channel is necessary. That's where the SK6812 RGBW LED comes into play.
It looks like any other addressable strip, but instead of 3 channels of color (24 bit), you load in an additional 4th channel for the white for a total of 32 bits per LED. This sort of data load may require careful use on microcontrollers with little RAM (460 LED limit for an Arduino UNO).
These are sold by the meter.
These are sold by the meter! You may or may not get a power connector pre-soldered to the end of your strip. The only way to be sure is to order a full spool (5M length). A set of 3-wire connectors may be a good idea.
NOTE: Being RGB/W means many standard Arduino addressable LED libraries are not entirely compatible. Until then, keep an eye on these libraries that do support it: