Venous leg ulcers affect >600,000 Americans costing $2 billion USDs yearly costs. Compression stockings and bandages are the standard of care in speeding healing rate. However, this therapeutic benefit requires a sub-garment pressure of at least 30-40 mmHg. Several medical associations have echoed the need for sensors capable of accurately, and repeatedly measuring interface pressure. PicoPress® (Microlabitalia, Padua, Italy) is the gold-standard. While accurate and repeatable, the air-bladder requires a larger base unit that precludes wearability, lacks wireless communication, and highly expensive (>$2,000 USDs). Using advanced materials science approaches, we report a flexible, battery-less, and wearable pressure sensor capable of wireless communication with any standard smartphone adhered between the human leg and compression garments. We fully encapsulate a piezoresistive sensor (Flexiforce 401, Tekscan, Boston, MA), underlying circuitry, and a NFC chip connected with serpentine copper interconnects to enable stretching and bending within a soft silicone elastomer. The 1.7 mm thick, 2 cm radius sensor (r2>0.95) from 0-100 mmHg with no appreciable hysteresis or drift. Preliminary testing on 3 healthy volunteers indicate minimal bending effects with excellent agreement (<10% mean difference) with PicoPress® from 0-60 mmHg in 10 mmHg increment applied through an adjustable inelastic compression stocking (Circaid Juxtafit, medi GMBH). This sensor has the potential to increase the real-world efficacy of compression garments. Future experimental testing should involve more human subjects of varying leg anatomies.