Paint Viscosity Cup Timing Calculator

Meta description (25 words): Measure paint flow time for sprayer-ready mixes quickly. Convert cup seconds into viscosity with calibration settings. Plan thinning, record batches, and export clear reports today.

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Calculator

Cup standard

Pick the cup family used for your test.

Cup number / orifice

Match the marking on your cup.

Efflux time (seconds)

Start timer at flow start; stop at first break.

Sample temperature (°C)

Warm paint usually flows faster.

Reference temperature (°C)

Common reference is 20 °C.

Temp coefficient (% per °C)

Heuristic correction; adjust for your coating.

Conversion mode

Calibrated mode estimates viscosity units.

Preset constants (optional)

Starter values only; verify accuracy.

Apply preset on submit

K (cSt/s)

Slope from calibration.

t0 (s)

Intercept time.

Density (g/mL)

Used to estimate dynamic viscosity.

Paint batch volume

Used for thinning amount estimate.

Paint volume unit

Pick the unit you measure with.

Target efflux time (seconds)

Optional: your sprayer or finish target.

Thinner output unit

Choose output unit for thinner.

Notes (optional)

Saved with your result for export.

Example data table

These examples show how timing and thinning estimates work. Replace constants with your calibration chart for accurate viscosity.

Standard	Cup	Time (s)	Temp (°C)	Mode	K (cSt/s)	t0 (s)	Est. cSt	Paint vol	Target (s)	Est. thinner
Ford	#4	30.0	20	Calibrated	2.50	0.0	75.0	1.0 L	24.0	0.25 L
Zahn	#2	24.0	25	Timing only	—	—	—	0.95 qt	20.0	0.19 qt
DIN	4 mm	18.5	18	Calibrated	2.20	0.0	40.7	500 mL	16.0	78 mL

Example thinner is computed by: thinner = paint × (1/ratio − 1), where ratio = target_time / current_time.

Formula used

Efflux timing: measure seconds for a fixed volume to drain through the cup orifice.
Kinematic viscosity estimate: cSt = K × (t − t0) (calibrated mode only).
Temperature correction (heuristic): cSt_ref = cSt × (1 + a)^(Tref − T), where a = temp_coeff/100.
Dynamic viscosity estimate: cP ≈ cSt × density (density in g/mL).
Thinner estimate: ratio = target_time / current_time, thinner = paint × (1/ratio − 1).

Cup conversions are not universal; use constants from your cup chart. This tool focuses on repeatable workflow, recordkeeping, and safe batch planning.

How to use this calculator

Choose your cup standard and cup number.
Run a clean cup test and enter the efflux time in seconds.
Enter sample temperature and your reference temperature.
For viscosity units, switch to calibrated mode and enter K and t0.
Add your batch volume and a target time to estimate thinner amount.
Click Calculate; then download CSV or print a PDF report.

Saved results (session)

Up to 50 recent calculations are kept in this browser session.

Time (UTC)	Cup	t (s)	Temp (°C)	Mode	cSt	cSt@ref	Thinner	Notes