Viscosity Converter Free Online
Convert dynamic (absolute) viscosity between Pa·s (SI), mPa·s, centipoise (cP), poise (P), kg/(m·s), and lb/(ft·s). Water at 20°C ≈ 1 mPa·s = 1 cP.
All Units
Pro — bulk batch conversion, API access, history & favorites
API access · Priority queue · Team workspace
Related Tools
Viscosity Converter Features
Fluids & Oils
Water 1 cP, motor oil 100–500 cP, honey ~10,000 cP, peanut butter ~250,000 cP, ketchup 50,000–100,000 cP.
7 Units
SI Pa·s, CGS poise/centipoise, imperial lb/(ft·s) and lb·s/ft². The cP and mPa·s are numerically identical — by design.
Lab & Industry
Lubrication, polymer melts, food processing, drilling muds, blood (3–4 cP), and ink formulation all use viscosity specs.
Live Conversion
Type a value, see all units instantly.
Swap Units
Quick reverse with the swap button.
100% Private
All math runs in your browser.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| Full viscosity conversion | ||
| Live conversion | ||
| All-units result panel | ||
| Bulk CSV / Excel conversion | — | |
| REST API access | — | |
| Custom precision settings | — |
Frequently Asked Questions
1 cP = 1 mPa·s = 0.001 Pa·s. Water at 20°C is ~1 cP, so memorizing this gives an intuitive baseline.
Dynamic (or absolute) viscosity is force-related, in Pa·s or cP. Kinematic viscosity = dynamic ÷ density, in m²/s or centistokes (cSt). This tool covers dynamic only.
SAE 5W-30 at 100°C ≈ 10 cP. SAE 10W-40 at 100°C ≈ 14 cP. At 40°C they are 50–80 cP. Cold start (winter "W" rating) viscosity matters most for engine wear.
By definition. 1 P = 0.1 Pa·s, so 1 cP = 0.001 Pa·s = 1 mPa·s. Engineers use them interchangeably.
Whole human blood at body temperature is 3–4 cP — about 3–4× the viscosity of water. Plasma alone is ~1.5 cP. Higher viscosity means harder pumping for the heart.