HTC One S has a pixel density of:
256.15

A.K.A.
Released: 2012

Resolution: 540×960 4.3″ display

Totaling 0.52mp (megapixels) and having a PPI of 256.15

Category: Phone
Tags:

HTC One S

Brand	HTC
Manufacturer	HTC Corporation
Series	HTC One
Compatible networks	GSM/GPRS/EDGE 850 900 1800 1900 MHz UMTS/HSPA (Z520m variant) 850 900 1700 1900 2100 MHz
First released	March 30, 2012
Availability by region	EU: 5 April 2012[1] US: 25 April 2012
Predecessor	HTC Amaze 4G, HTC Sensation
Successor	HTC One Mini
Related	HTC One X, HTC One V, HTC One XL
Type	Smartphone
Dimensions	130.9 mm (5.15 in) H 65 mm (2.6 in) W 7.8 mm (0.31 in) D
Mass	119.5 g (4.22 oz)
Operating system	Android 4.0 Ice Cream Sandwich, HTC Sense 4.1 overlay, Upgradeable to Android 4.1.1 Jelly Bean and HTC Sense UI 4+ (Update to Sense 5 discontinued)
System on chip	Qualcomm Snapdragon S4 Plus MSM8960 for Z520e variant[2] and Qualcomm Snapdragon S3 MSM8260 for Z560e variant
CPU	1.5 GHz Dual-core Qualcomm Krait for Z520e variant or 1.7 GHz Dual-core Qualcomm Scorpion for Z560e variant
GPU	Adreno 225 for Z520e variant or Adreno 220 for Z560e variant
Memory	1 GB RAM
Storage	16 GB
Removable storage	No
Battery	1650 mAh internal rechargeable li-ion
Data inputs	ambient light sensor, digital compass, G-sensor, gyroscope, multi-touch capacitive touchscreen, proximity sensor
Display	4.3 in (110 mm) Super AMOLED with RGBG-matrix (PenTile) qHD (540×960) resolution covered with Gorilla glass
Rear camera	8-megapixel (3,264×2,448) with autofocus, smart LED flash, BSI sensor, 1080p HD video recording
Front camera	VGA
Connectivity	3.5 mm stereo audio jack Bluetooth 4.0 with aptX enabled Wi-Fi: IEEE 802.11b/g/n DLNA micro-USB 2.0 (5-pin) port with mobile high-definition video link (MHL) for USB or HDMI connection
Other	HTC Sense 4.1 user interface
SAR	Head: 0.393 W/kg 1 g Body: 1.181 W/kg 1 g Hotspot: 1.181 W/kg 1 g[3]
References	[1]

This righthand infobox courtesy of Wikipedia.