







Roll of film 
20211120 

From Brian: Trying to create a formula to calculate the build up on a roll of film is calculated. Except instead of of a roll, it's essentially a rectangle with two semicircles on each at the end.
Example: I start with a 6" diameter core on each side, and I start winding .005"
thick film on the core. The distance between the center of those cores, length of the inner rectangle is 7.125.
If I continue to do this for a total length of film of 3000 feet, what will the
roll length and width be.
So what I need is the formula to perform this type of calculation.
Can you help me? I want to be able to plug the formula in a spread sheet and to be able to input a core diameter, a film thickness and a total length and the length between the center of the two cores(which is the inner rectangle's length I'm assuming).
Thanks Answered by Harley Weston. 





More on a roll of paper 
20210507 

From Stephen: Can you help with the equations to calculate the length of paper required to
achieve a target outside diameter when wrapped around a core please?
The inside diameter of the cardboard core is 76mm
The thickness of the wall of the cardboard core is 5mm
The thickness of the paper is 138microns
The desired outside diameter of the finished roll is 320mm
I hope you can help me with a solution, Thank you Answered by Harley Weston. 





The area and weight of sod 
20181211 

From Susan: I have equipment that will cut sod 30 inches across and 75 Feet in length?
how much will this be in square foot age ? Yards? Approximate weight? Answered by Penny Nom. 





The amount of material remaining on a roll 
20161111 

From Yoh:
Question from Yoh:
Hello,
I am trying to find impressions on a roll (either full roll or partial).
Let's say I have the following information.
 Outer Diameter of roll
 Inner Diameter of roll (cardboard core)
 thickness per layer
 Each cut off length (impression length)
Now let's say a roll has a 40in outer diameter, the cardboard core has a 3.75in diameter and a thickness of .002. Each impression has a cut off of 14inches.
With this the roll will have approximately 2,700 impressions. How would I find the remaining impressions if the outer diameter of the roll is only 6.5inches?
Thank you. Answered by Penny Nom. 





The length of stock on a roll 
20160923 

From Ken: I have a roll that is 13.5 inches wide ( OD) , and is wound on a 3 inch core. the thickness of the material is 3.5 thick.
Do you know of a formula that can calculate the linear feet on that roll?? Answered by Harley Weston. 





The length of a roll of paper 
20150112 

From Peggy: roll of paper 3ft wide and roll equals 500 sq ft how long would the roll be? Answered by Penny Nom. 





Rolls of window film 
20140214 

From Travis: This question is probably close to the same question as "roll of paper"
We have Rolls of Window Film that we are trying to figure out an equation for a spreadsheet that we can use to "inventory" our window film.
We use a caliper tool to measure the thickness of the roll in millimeters.
the core thickness = 1.90mm
Full Roll thickness(including core) = 9.08mm to 9.12mm
Film thickness = 0.06
Full Roll of Film is supposed to average 1200" of film
What equation could we use to get the approximate inches left remaining on the roll if we measured the roll including the core with the Caliper tool in Millimeters? Answered by Harley Weston. 





A steamroller with a 3 foot diameter and a 6 foot width makes 20 revolutions 
20120321 

From Robert: A steamroller with a 3 foot diameter and a 6 foot width makes 20 revolutions. How much ground area does it pave? Answered by Penny Nom. 





A reel of paper 
20110603 

From keith: if a full reel of paper has 7750 metres on it with a diameter of 1240mm and a core diameter of 100mm how can work out the thickness of each strip of paper therefore allowing me to work out the metreage of the roll when its half in diameter at say 620mm Answered by Penny Nom. 





How many labels are left on a roll? 
20100813 

From Melissa: Is there a simple way to calculate how many labels are left on a roll? I thought there was a way to look at the individual label length, the label thickness and the core diameter and then measure the overall diameter to calculate how many pieces were left, but I'm struggling. I've seen a tool before I thought we called it a circle calculator, but those parameters were all that I needed to input to spit out the correct count. I never saw what was behind the scenes for this calculation. Ie factoring in revolutions or the number of pieces on each layer, etc. Please let me know if you have any suggestions. Any assistance will be greatly appreciated!!! Thanks! Answered by Penny Nom and Tyler Wood. 





A roll of paper 
20100325 

From keith: how many yds of paper for a roll with a width of 6.875 and a core of 3 in and a diameter of 40in? Answered by Robert Dawson. 





A paper towel roll 
20090819 

From Jeff: I am making a spiral tube with paper that is 2" in dia. and 102" long
I will be using paper that is slit 3" wide how many lineal feet of paper will
I need to to cover the 102"
I will be using 3 rolls of paper that will over lap the other by half to make
a hard tube (paper core) in a roll of paper towels
Thanks Jeff Answered by Penny Nom. 





A roll of paper 
20090705 

From mark: is there a simple way of finding out how much is left on a roll of paper. i have read similiar questions and answers on here but all seem very complicated and not being very good at maths does not help me much. some are in inches and all have different figures to mine so if i give my figures hopefully i wil understand it better. the radius of the cardboard core is 52.25mm, the radius of the paper at 2000 linear meters is 158.625mm. the thickness is 0.17mm. when nearing the end of the paper how do i work out how much is left in a simple way. thank you in advance for any help you can give me Answered by Harley Weston. 





Winding paper after a break 
20090410 

From Olen: Question from Olen:
I work in a paper mill and have been handed the task to search for a formula to determine how much paper needs to be added to a parent roll to make up the difference at the winder. (Ex. The spool diameter at the reel is 18.25" we measure roughly 33.5" to make two 58" rolls in the winder. If the is a paper break and the roll diameter in the winder is 30" how much do I add to a single parent roll (22" roughly) to make one 58 " and the 28" needed at the winder. I would appreciate any help to complete this task. I would like to be able to build a chart that operators can refer to based on what is needed. Thank you. Answered by Harley Weston. 





A spherical Tootsie Roll Pop 
20090401 

From Tracy: A spherical Tootsie Roll Pop you are sucking on is giving up volume at a steady rate of .8 ml/min. How fast will the radius be decreasing when the Tootsie Roll Pop is 20 mm across? Answered by Harley Weston. 





Payroll deductions 
20090329 

From Jim: I want to set up a spread sheet where i can enter my hourly pay or gross income,
and calculate my tax deductions. I have my old pay stubs but I am stuck when I
take the amount of the deduction and try to figure out the % used to calculate the amount
for example gross pay $1359, EI= $64, Fed Tax=$129, Prov tax = $35
these numbers I have provided are random but I think you can get the idea Answered by Penny Nom. 





The diameter of a roll of plastic 
20090324 

From truong: hi. i have trouble to calculate the diameter of the plastic roll. the sheet is 765 m long and 0.8 mm to wrap around the core 400 mm in dia. please help me with the formula to calculate the dia of plastic roll, thanks in advance Answered by Harley Weston. 





A roll of film 
20081016 

From John: I need to know how to calculate the build up on a roll of film is calculated.
Example: I start with a 6" diameter core, and I start winding .005" thick film on the core, so I am adding a total of .010" to the diameter each wrap.
If I continue to do this for a total length of film of 3000 feet, what will the roll diameter be?
So what I need is the formula to perform this type of calculation.
Can you help me? I want to be able to plug the formula in a spread sheet and to be able to input a core diameter, a film thickness and a total length and get a roll diameter. Answered by Penny Nom. 





A roll of paper 
20080305 

From Sheik: How I Convert My Roll Weight Into Meters?
Roll Width : 241mm
Thickness : 56gsm
Weight :81 Kg Answered by Harley Weston. 





Rolling a die repeatedly (you can't just add percentages) 
20071004 

From Howard: If my son has a 16.66% chance of rolling a particular number on a dice,
and he rolls for it 6 times, he knows (from experience) that his
odds of getting at least 1 right are not 100% (16.66% +16.66%+16.66% etc).
He asked me if there was an equation that would give him the correct
percentage chance of success when trying X times for a Y% chance
of something. Answered by Victoria West. 





Rolling a metal plate 
20070731 

From k.a.suresh: How to calculate the plate size for rolling (2010mm OD)plate thick is 6mm Answered by Harley Weston. 





Rolle's Theorem 
20061207 

From Erika: If f(x) = (x^2)(square root of [3x]) on the interval [0,3] is given, Does Rolle's Theorem apply? If yes, find any values of c such that f '(c)=0 Answered by Penny Nom. 





Grossing up payroll wages 
20060827 

From Katie: I really need to understand (spelled out step by step) how to gross up payroll wages. Answered by Penny Nom. 





Linear feet on a paper roll 
20060320 

From Vishal: I WOULD WISH TO KNOW OF A STANDARD FORMULA BY WHICH I CAN CALCULATE THE LINEAR FEET OF A PAPER ROLL AS PER THE FOLLOWING DETAILS:
THICKNESS: 150 GSM (GRAMS PER SQUARE METER)
REEL WIDTH: 85 CM
REEL DIAMETER: 140 CM
REEL INNER CORE: 10 CM
REEL WEIGHT: 946 KG's
Answered by Stephen La Rocque. 





A roll of paper 
20050416 

From Tuomas: How would you calculate a diameter of a paper reel when the paper is 0,04 millimeters thick and for example 5000 meters of it is winded on a 76 mm (3inch) core. Answered by Penny Nom. 





The length of fabric in a roll 
20030703 

From Paul: We receive rolled fabric as part of our process and I would like to know is there a formula that could be used to estimate the overall length of the roll with out rolling the fabric out and measuring its length. Answered by Harley Weston. 





The Terror Run 
20000318 

From Danny Mclean: A fairground's most popular attraction is a roller coaster ride known as the Terror Run. One stretch of track is called the Missile Path and is in the form of a parabolic curve. B is 180m horizontally from A and the highest point of the curve is 100m above A and B. A.. The owner works out a quadratic expression to describe the Missile Path. What is the expression He found? B.. A safety Engineer examined the structure and observed that points A and B were likely to be damaged due to the steepness of the Missile path near these points. The owner can see no way to make the Missile path less steep near A and B and to keep the height of the ride the same. HOW CAN IT BE DONE? Answered by Harley Weston. 





A roll of paper 
20000115 

From Richard: I have a roll of paper, wrapped around a corrugate core, whos diameter is 10.750 in. The outer diameter of the roll is approx. 60 in. The thickness of the paper is .014 in. I am trying to find out how much linear feet of paper is left on the roll, given only the diameter of paper remaining on the core. Answered by Chris Fisher and Harley Weston. 





Trolls and Gargoyles 
19991102 

From TexGrimm: How can you seat 6 monsters  3 Trolls and 3 Gargoyles at a circular table if the trolls look alike and the gargoyles look alike? Does your formula work for 9 monsters  4 trolls and 5 gargoyles? Answered by Penny Nom. 





Rolling Circles 
19990912 

From Craig Ellis: We have a circle of radius 3. inside the circle and tangent to the circle of radius 3 at one point is a circleof radius 1. The question is if we could roll the smaller circle around the inside of the larger circle how many revolutions would it take to get around to where we started. Answered by Chris Fisher and Walter Whiteley. 





Three dice 
19981117 

From Ryan Allinson: Rolling three regular dice how many different ways could a sum of 10 be rolled? Hope you can help. Can you please show me how this is done? Answered by Penny Nom. 





Rolling a seven 
19980611 

From Bruce Thompson: What is the probablity of rolling two dice and it coming out as seven? a) 1/6 b) 1/36 please give me the correct awnser and explain please. Answered by Harley Weston. 





Sens d'un mot 
20000601 

From Edward Brisse: Seraitil possible de connaître le sens précis du mot "PORISME". Exemple : "le porisme de Poncelet". Answered by Claude Tradif. 

