New Guardian® Acoustic Calculator 3.0

Using the new Acoustic Calculator 3.0 is now easier than ever before: upon launch, a set-up assistant helps guide you through a set of relevant questions aimed at reducing the 70 million possible configurations to a manageable number, before giving you the flexibility to refine the data to suit your needs in the results table.

Should you not wish to use the set-up assistant, you can jump straight to the table, where the database works in a similar way to previous versions of the Guardian®  Acoustic Calculator, allowing the columns to be filtered and narrowing the options until you identify a set of glass solutions suitable to meet the acoustic requirements specified.  The system will only display up to 50 options at any one time, so we wound encourage filtering the columns with more accuracy to help focus your results.


Set-up assistant

The set-up assistant is designed to help guide you in creating the table and refining the 70 million possible results, so that you are presented with a manageable amount of data by the time you get to the table itself. 

The set-up assistant offers you two ways to start calculating your acoustic enquiry:

1)    Calculate the acoustic performance of glazing

By entering the specific details of your glass combination, the set-up assistant will refine the data and provide you the acoustic results for the proposed glass configuration.

2)    Find glazing solutions for a specific acoustic performance

This allows you to take an acoustic specification, enter it into the system, and find glazing solutions which meet the specified acoustic performance required.

Important Note:  The Acoustic Calculator is only as good as the data you have to enter into it, the tool is most effective when you either have a glass configuration you want to calculate or an acoustic specification which requires a glass solution to achieve the specified performance.  Gather the information you have together before using the calculator, and you will find answering the questions asked by the set-up assistant easier, delivering the results you need more quickly.

Cavity width filtering

Before refining the main body of data you have the option to identify any unit parameters which may restrict you, such as the overall insulating glass unit thickness or any cavity ranges which may be necessary to achieve the right U value (thermally insulating) performance.  By entering your maximum available unit thickness, and then identifying the minimum and maximum cavity widths, you can restrict the results presented in the table below to match your specific requirements.  When entering a unit configuration which may include triple glazing, or both double and triple glazing, add the total cavity space available together and enter those as the minimum and maximum cavity width available.  In the case of triple glazing the filter will automatically divide these cavity widths between the two cavities to ensure the correct results are displayed.

Filtering columns

You can select multiple items in each filter column to refine your search.  Consider which dB values you want to achieve as well as the octave frequencies, if specified, then consider the glazing construction, i.e. single, double or triple.  Continue to refine your search by considering the glass type and thickness you might want to use in relation to other factors such as manufacturing capability, safety and thermal performance; you can determine thermal performance using our glass Performance Calculator.


Version 3.0 of the Guardian®  Acoustic Calculator allows you to select cavity widths from 10mm to 24mm at 2mm intervals.  Although It is recognised in EN standards such as EN 12758 and EN 12354-3 that there is little change in acoustic performance in cavities up to 24mm in width, this latest version of the Acoustic Calculator allows you to identify the point that the dB and octave frequencies change as you increase cavity thickness, allowing for a greater level of accuracy.  To enable a more manageable number of acoustic configurations, the calculator omits cavity thicknesses of less than 10mm as the change in acoustic performance at this point is virtually undetectable.  It’s considered reasonable to assume the acoustic performance will remain the same for cavity widths of less than 10mm. 

Filtering triple glazing

When filtering glass thickness in triple glazed configurations, refine the inner and outer glass thicknesses before considering the centre pane. The centre pane may need to be heat treated to avoid risk of thermal failure and therefore may restrict your available unit configurations.  In terms of acoustic performance, the position of the glass has less of an impact, it is more the types and thickness of glass used in combination that will impact final performance.

Alternative filtering

If you have already specified the glass configuration and you want to know the acoustic performance it provides, simply filter the columns according to the glazed configuration. The performance values will be displayed with either calculated or certified results available for download.

PVB and sound reduction PVB interlayers

The PVB interlayer in a laminated pane of glass can contain as many as 4 sheets between any two panes of glass, with each PVB interlayer measuring0.38mm in thickness.  A sound reduction laminate can contain as many as 2 acoustic PVB interlayers, each acoustic PVB interlayer is both thicker and less dense than standard PVB, allowing for better sound reduction. A sound reduction PVB interlayer can measure up to 0.76mm in thickness.

Laminated glass names and descriptions

There are a number of industry terms used to describe the glass/PVB build-up of laminated and laminated sound reduction glass.

The Acoustic Calculator uses the common, pan-European method of showing the panes of glass and the PVB separated by a dot.  For example, 33.1 which is equal to 2 x 3mm panes of glass and 1 x PVB or Acoustic PVB interlayer.

However, there are other industry terms which are used to define the makeup of a laminated pane of glass, these include using the total thickness of glass rounded to one decimal place.  For example, a 33.1 laminate may also be defined as 6.4, which is the total thickness of glass (3+3) and the total thickness of one PVB interlayer (0.38mm).  Another example may be 88.3 laminate, which can also be defined as 17.1 using this method, as the total glass thickness is 16mm (8+8) and the total PVB thickness is 1.14mm (3 x 0.38mm).

For further information on laminated glass construction please visit the Guardian® Glass website.

Table Contents 

The table layout and content from left to right:

Red cross

This enables you to delete configurations after you have filtered the other columns, so that you can display just the unit configurations appropriate to you and your business.  Don't worry, the deleted lines will never be lost - simply reset the table to retrieve all the data.

Calculated result or certificate

Here you will find a hyperlink to the calculated results page, this details the glass configuration and acoustic performance including the octave centre frequencies, as well as Rw, Rw + C and Rw + Ctr.  The results page also details the total weight of the glass specified and the total thickness of the glass combination including cavity once sealed into an insulating glass unit.    Where certified results are available for some constructions tested by institutes / test houses for constructed units, these will be available for download instead of providing the calculated result.


Here you can select whether you are specifically looking for single, double or triple glazing configurations, if you want to select from all three, tick all of the glazing options, or select “Any”.

Glazing construction

The next eight columns allow you to refine the glazing construction based on the glass type, thickness and the cavities selected.  The final column of this section shows the total thickness of the glass configuration, this allows you to filter the data based on the maximum IGU thickness available for your frame or system.

Glass unit performance

Rw [dB] performance of the glass or unit.

Rw + C performance of the glass or unit with regards to pink noise*.

Rw + Ctr [dB] performance of the glass or unit with regards to traffic noise.

*Pink noise refers to general background noise; TV, talking, music, etc, mid-high frequency noise as outlined in ISO 717 

Octave centre frequency performance

The final columns are the octave centre frequency performance, with dB reductions at 125 to 4000 Hertz. These are often required to provide a more detailed performance of the glass.

Performance figures

The acoustic performance of windows and glazing assemblies may be defined by a number of terms; the most common being the acoustic performance measured at octave centre frequencies of 100 to 4000 Hertz. The attenuation of various glass configurations needs to be established by measurement and used as a guide to the acoustic attenuation performance of the glass. There are also single figure acoustic indices, the two most commonly used being the weighted reduction, Rw, which includes a correction for the varying sensitivity of the human ear at different frequencies and traffic noise reduction, RA,tr, which is relative to a standard traffic noise spectrum. The above terms have now been integrated into a single number quantity in accordance with EN ISO 717-1, which defines three terms as follows;

Rw (C;Ctr) Where Rw is called the weighted sound reduction index, which takes account of the human ears sensitivity to a range of frequencies and may be used to compare the performance of alternative products. C is the adaptation term for pink noise, which considers higher frequencies and is determined by the equation

(Rw + C) = RACtr is the adaptation term for the traffic noise spectrum, which considers lower frequencies and is determined by the equation (Rw + Ctr) = RA,tr

For further information regarding acoustic performance solutions and Guardian's range of laminated glass products with special sound control features please refer to our specific documents which can be obtained from the Guardian Technical Center


New to Version 3.0 of the Guardian Acoustic Calculator is the calculation of the weight of the glass and PVB (if laminated with standard or acoustic PVB) in each glass configuration.  The weight is based on a square meter of glass, which can be factored up or down depending on the size of the glass being installed.

Printing data

Once you have selected the data you require by refining the filters for each column, you can print a range of unit constructions which achieve the required acoustic performance. This can be supplied to your customer to show the options available to suit their needs.  Remember if there are unit constructions in the list that are not commercially viable for your business, you can delete these using the red cross on the left hand side of the table.

To print data either click on the options button in the top right hand corner of your browser and select print, or right click on your mouse anywhere on the web page and select print from there.  Note: you may need to change the print option from portrait to landscape to ensure that all data is visible on a single page.