Paper Mill Calculator & Tools puts the calculations of the paper mill in your pocket: unit conversions, paper machine formulas, stock preparation and laboratory tests, with no login and no data collected.

Most calculators work in both directions: enter any of the values and the missing one is calculated. Values you type in are never sent anywhere, and the app works offline.

UNIT CONVERSIONS
• Pressure, flow, volume, length, mass, force, power, energy, specific energy, temperature, machine speed, production, basis weight, nip load, caliper, consistency, vacuum (relative or absolute), wire and felt tension, chemical dosing and more
• About 300 units, including m³/d, MGD, MWh, GJ, t/y, quintal, CV, °f, kgf/cm and N/15mm
• US paper grades and ream weights (Bond, Bristol, Index, Cover, News, Text)

PAPER MACHINE
• Machine production from width, basis weight and speed (and the other way round)
• Headbox jet speed, jet-to-wire ratio and wire speed
• Headbox flow
• Theoretical slice opening
• Reel calculator: weight, length, width and basis weight
• Water to evaporate in the dryer section
• Crepe ratio for tissue machines, with Yankee or Pope reference and basis weight at the Yankee and at the Pope
• Basis weight change, starting from stock flow or production: new flow, production or machine speed for the next grade
• Save the sheet width of your machines and reuse it in the other calculators

STOCK PREPARATION
• Production from flow and consistency
• Pipe flow: flow, velocity and diameter
• Node flow balance
• Pulper water for a batch of fiber
• Tank dilution: water to add to reach a lower consistency
• Tank volume: capacity of a cylindrical tank and the stock it can hold
• Refiner specific energy (SRE), net and gross, in kWh/t, kWh/ST, MJ/t or HPD/T
• Centrifugal pump power: shaft power range from flow, head and impeller type, with the suggested motor size (IEC kW or NEMA hp)

LABORATORY
• Guided consistency, paper dry content, ash, Cobb and TSS (total suspended solids) tests, with drafts you can resume and a history of the last tests
• First pass retention
• Breaking length and tensile index
• Laboratory unit conversions and basis weight conversions

MADE FOR THE MILL
• Large fields and drum pickers designed for quick use on the phone
• Built-in calculator: write the whole expression with parentheses, log and functions, keep a history of the last calculations and paste the result into any field
• Lock the values you know: a locked field is never overwritten
• Every field remembers the last unit you chose
• Arrange the cards in the order you prefer
• Help on every screen, with short video tutorials
• Reduced lists of practical units in each calculator, plus the full list in Conversions
• Available in English, Italian, Spanish, Portuguese and French

Suggestions for new calculators are welcome: write to seavtools@gmail.com.

Independent tool, not affiliated with or endorsed by TAPPI, ISO or any other organization mentioned. Results are indicative; verification remains the user's responsibility.