• mobile_phones
  • Model Assumptions

    In general, mobile users may not be aware of every aspect of their mobile phone use. Therefore, in order to assist users and to contribute towards an accurate cost comparison, callcosts.ie uses a number of assumptions in making a calculation. Where possible industry data has been used to develop the assumptions listed below. 

    When most calls are made

    To run a calculation, callcosts.ie needs to know when you mostly use your phone and the mobile calculator provides a number of time periods for you to choose from. The reason why you are asked this question relates to the way in which mobile service providers call costs differ depending on the time of day you call. The time periods presented by the mobile calculator have the following associated time of day/weekly distributions:


    Breakdown of Weekly Usage

    DaysAnytimeWeekendMonday to Friday DaytimeMonday to Friday EveningsMonday to Friday Daytime and EveningMonday to Friday Evenings and at weekendsMonday to Friday Daytime and at weekends
    Weekday 70% 20% 80% 80% 80% 70% 70%
    Weekend 30% 80% 20% 20% 20% 30% 30%

    Breakdown of Daily Usage

    HoursAnytimeWeekendMonday to Friday DaytimeMonday to Friday EveningsMonday to Friday Daytime and EveningMonday to Friday Evenings and at weekendsMonday to Friday Daytime and at weekends
    00.00 to 06.00 5% 5% 5% 5% 5% 5% 5%
    6.00 to 12.00 25% 25% 35% 5% 15% 5% 35%
    12.00 to 18.00 35% 35% 55% 15% 40% 15% 55%
    18.00 to 24.00 35% 35% 5% 75% 40% 75% 5%


    Here is an example how the  distribution works for the 'Anytime' option. If you use 100 minutes per month and you choose the anytime option, the minutes will be distributed as follows

    • Weekly Breakdown - 70 minutes (70%) are made during the week and 30 minutes (30%) are made at weekends
    • Cumulative Daily Breakdown – For the relevant period, 5 minutes (5%) of your minutes used will be between midnight and 6.00am, 25 minutes (25%) are between 6.00am and midday, another 35 minutes (35%) are between midday and 6.00pm and the final 35 minutes (35%) are made betweem 6.00pm and midnight. 

    Which mobile networks you call and text

    Given mobile operators can charge different rates depending on the network you call the model needs to take account of this in making a calculation. In order to increase the accuracy of your calculation callcosts.ie distributes your minutes used across each of the mobile operators' networks. This distribution assumption is based on each mobile operator's market share as it provides a good indication as to which networks your called minutes are likely to go to. The current market shares used on the calculator for distributing minutes across mobile operators' networks are as follows:

    • Vodafone 42.2%
    • eir Group 18.8%
    • Three Group 34.2%
    • Tesco Mobile 3.6%
    • OAOs 1.1%

    Please note that you can alter the distribution of minutes to operators' networks by clicking on the 'Enter More Detailed Usage' button at Step 1 of the calculator (This button is located at the end of the first screen)

    Mobile operators may also offer different rates for texts to mobile users on their network as opposed to other networks. The text distribution assumption applies the same operator market shares listed above.

    How many of your minutes are voicemail calls

    The website also assumes that some of the minutes that you enter into the model will go to voicemail. It is important to include voicemail costs in the calculation as one operator may offer a free voicemail service, the use of which does not affect your inclusive minutes whilst another may charge for the service. Callcosts.ie assumes that 5% of the minutes that you enter will go to voicemail.

    Minutes allocated to preferred numbers

    Some operators may offer discounted or free minutes for calls to between 1 and 2 phone numbers. Typically, such ‘preferred number’ schemes can have one or more of the following usage conditions:

    • they must be a mobile number(s) on that operator's network and may also include calls to a landline number(s), and
    • they must be nominated by the user and notified to the operator.

    The mobile calculator assumes that 5% of the total minutes you entered in Step 1 qualify for ‘preferred number’ offers if such offers are available from an operator. If an operator does not have a 'preferred number scheme' the number of assumed minutes (5%) will go back into the calculator and be rated as appropriate. You should note that it is possible to change the number of 'preferred minutes' entered on the 'Enter More Detailed Usage' screen.

    The number of calls that will incur a minimum call charge

    Some operators may charge a minimum charge per call irrespective of its duration. High minimum call charges can have an impact on your costs, particularly where calls are of a short duration. 

    For example, if a mobile to mobile call costs 40 cent per minute and the operator levies a minimum call charge of say 10 cent, then any call lasting less than or equal to 15 seconds (calculated by dividing the 10 cent by the 40 cent and multiplying it by 60 seconds) will incur the minimum call charge i.e. a 5 second call would incur the 10 cent minimum call charge. Once the duration of the call passes 15 seconds it is charged normally. So the total cost of a 60 second call in this instant would be 40 cent.

    To increase the accuracy of your calculation, callcosts.ie makes an assumption that a set number of calls need an adjustment to take the minimum call charge into account.  If an operator levies this charge, the mobile model makes an assumption that 5% of calls will be adjusted to take the minimum call charge into account.

    Assumption regarding add-ons and pre-paid discounts

    In providing a result, callcosts.ie assumes the user will choose tariffs/payment options and features available which if availed of can lower their costs. Consequently, callcosts.ie will calculate if a top-up discount or a tariff add-on feature can lower the cost to the user and, if so, indicate whether this feature has been included in the calculation when providing a result.  It is assumed that the user will purchase the add-on or will top up by the required minimum top-up level in order to avail of the benefit.  Please note a top-up discount will only apply where the users spend level passes the initial threshold at which the top up discount becomes available.