The calculation, without hidden assumptions
Estimate the paper-only mass wound on a reel while keeping the two physical models visible: annular geometry estimates web length from OD, core OD and caliper, then GSM converts web area to mass. Add known core mass only when you actually know it.
How to use this calculator
Measure finished roll OD, the core outside diameter where paper begins, and web width.
Enter total paper caliper using a supplier specification or representative measurement.
Enter paper grammage in GSM. Keep coatings included when the stated GSM and caliper describe the coated finished sheet.
Optionally enter known core mass, roll quantity and a measured net paper weight to compare theory with production.
Use the substituted working to audit units before relying on the estimate.
Where people use it
- •Estimate reel mass before converting, printing or warehouse handling.
- •Plan paper-only shipment tonnage across multiple identical rolls.
- •Cross-check a supplier reel specification using OD, caliper and GSM.
- •Compare a measured net roll with geometric theory and derive effective GSM for troubleshooting.
- •Estimate web length and area without unwinding the roll.
1,000 mm OD paper reel
A 1,000 mm OD reel on a 76 mm core, 1,000 mm wide, with 100 µm caliper and 80 GSM contains about 7,808.6 m of ideal web and about 624.69 kg of paper before core or wrapping mass.
What the result does not assume
- •Use core outside diameter, not nominal core inside diameter. Core wall thickness varies.
- •This model assumes concentric, tightly wound geometry with uniform caliper; real winding compression and telescoping can change effective length.
- •GSM measures mass per area and caliper measures thickness. Do not silently infer one from the other without a verified material density/bulk assumption.
- •Core, plugs, wrapping, labels, straps and pallets are excluded unless their known mass is explicitly added.
- •For forklift, hoist, unwind-stand, freight or contractual limits, use a calibrated scale and applicable equipment/carrier rules.
Frequently asked questions
How is paper roll weight calculated from diameter?+
First calculate theoretical web length from the annular wound cross-section and paper caliper. Multiply that length by web width to get area, then multiply area by GSM.
Does the result include the core?+
The primary result is paper-only. If you know the actual core mass, enter it separately to obtain a gross roll estimate.
Should I use core ID or OD?+
Use the core outside diameter where the wound paper begins. A nominal 3-inch core often describes the inside diameter, so it is not automatically the correct value.
Why do I need both GSM and caliper?+
Caliper converts wound geometry into web length; GSM converts web area into mass. Papers with the same GSM can have different thickness because bulk and coating differ.
Can I use inches?+
Yes. Diameter and width can use inches, while caliper can use micrometres, millimetres, mil or inches; the solver normalizes them before calculation.
Why can measured weight differ?+
Manufacturing tolerances, moisture, coatings, compression, imperfect diameter measurements and winding tension all affect real rolls. The optional measured-net input reports variance rather than hiding it.
Semantic next steps
Continue the calculation
These links move to a different input, formula or project stage rather than a keyword variation of this page.
Roll Length Calculator — Diameter, Core & Thickness
Estimate paper, film, foil, tape or fabric length from roll diameter, core diameter and thickness, with wraps, area, percent remaining and measured-roll calibration.
OpenPaper Weight Calculator — GSM, Sheet, Ream & Print Run Weight
Calculate paper weight from GSM, sheet dimensions and quantity. Compare per-sheet, pack, 500-sheet ream, total kg and lb, with custom sizes and packaging.
OpenLabel Roll Calculator — Labels Per Roll, Remaining & Diameter
Calculate labels per roll from OD, core, caliper and pitch; estimate labels remaining, multi-lane yield, waste, target diameter and effective caliper from a verified count.
OpenGross Shipment Weight Calculator — Net, Cartons & Pallets
Calculate cargo gross weight from product quantity, net weight, unit packaging, carton tare, pallets and other packing, with optional container tare and a complete weight audit.
OpenFilm Weight Calculator — Gauge, Width & Roll Length
Calculate plastic film roll weight, length, width or thickness from density, gauge and dimensions, with GSM, area and optional core weight.
OpenCoil Weight Calculator — OD, ID, Width & Density
Calculate theoretical steel or metal coil weight from OD, ID, width and density, plus PIW, strip length, run time, capacity utilization and reverse maximum OD.
OpenShrink Film Size Calculator — Centerfold & Sleeve
Estimate centerfold shrink film width, cut length, batch consumption and sleeve layflat from package dimensions with explicit seal allowances.
OpenPoly Bag Size Calculator — Flat & Gusseted Bag Fit
Estimate minimum flat or gusseted poly bag dimensions from product width, depth and length with explicit loading and closure allowances.
OpenFree publisher widget
Put this calculator on your website
Give readers the live calculator without rebuilding the math. Copy the responsive embed in one click, or customize width, height, border and corner radius before publishing. The branded MAXScanner attribution stays visible.
Calculator embed HTML
Paste this code into your page. Focus the code box to select it manually.
Keep the result connected to the real job
MAXScanner keeps the formula and assumptions beside the result so you can verify the number before using it in a drawing, estimate, specification, worksheet or document. Where a supplier, manufacturer, drawing or applicable standard owns a requirement, that source remains authoritative.