Rent & Mesne Profits Calculator

New Square Chambers is pleased to make available the following calculator, which is freeware and can be used from this website without charge. Full instructions for using this Rent and Mesne Profits Calculator, and important legal notices, are further down this page.

• Instructions

  Step 1 – Choose the date of the first missed instalment of rent
  Select the starting date of your choice using the popup date selection window. When you first open the Rent Calculator, the date is automatically set to today’s date. As the calculator takes today’s date from your system clock, it is important to make sure that your system date is correctly set for this function to work properly.

  Step 2 – Choose your ending date
  Select the ending date of your choice using the popup date selection window. When you first open the Rent Calculator, the date is automatically set to today’s date. As the calculator takes today’s date from your system clock, it is important to make sure that your system date is correctly set for this function to work properly.

  Step 3 – Enter the amount of each instalment of rent
  You should not enter any currency sign, nor should you enter any commas in the number.

  Step 4 – Select the period for the payment of rent
  Select the period for the frequency with which rent is due (daily, weekly, etc.). Further information is available on the “usual quarter days” and see also the Historical Note on Quarter Days at the bottom of this page.

  Step 5 – Calculate
  Press the button marked “Calculate” to carry out the calculation. In the lower part of the form will be displayed the number of instalments of rent which have been missed, the total of the current arrears (rounded to two decimal places) and the daily rate at which arrears continue to accrue (again rounded to two decimal places).

  Method of calculation:

  The answers above include the instalment of rent due on your chosen starting date (step 1 above) and also any instalment of rent which may fall due on your chosen ending date (step 2 above). The continuing daily rate is calculated by taking the equivalent annual amount of rent and dividing by 365, except in the case of rent due weekly where it is calculated by dividing the weekly instalment of rent by 7. It makes no difference to the calculation itself whether rent is payable in advance or in arrears, although you should bear in mind that where the rent is payable in arrears you will need to use the continuing daily rate if you wish to calculate the total sum due to the present day since the last instalment of rent fell due.

  Problem dates:

  (1) Where the starting date exists in the starting month but not in the ending month (e.g. a calculation from 31 January to 30 September), then for the purpose of monthly and six monthly calculations the calculator assumes that another full month has accrued if the ending date is the last day of the ending month. So, for example, 31 January to 30 April is four instalments of monthly rent (i.e. it includes the April instalment) but 31 January to 29 April is only three instalments of monthly rent (i.e. it excludes the April instalment).
  (2) No equivalent correction is needed or made when the calculation goes from a shorter month to a longer one. So, for example, 30 April to 30 May is two instalments of monthly rent (i.e. it includes the May instalment) regardless of the fact that other days still remain in May.
  (3) The above points take account of leap years. In other words, the last day of February for these purposes is normally the 28th but in a leap year would be the 29th.
  (4) An equivalent problem occurs in respect of annual calculations but only when the date of the first missed instalment is 29 February (an unlikely scenario). In these circumstances the calculator assumes that another full year from 29 February has accrued if the ending date is 28 February in a normal year or 29 February in a leap year.
  (5) Again, no correction is made if the first missed annual instalment is 28 February. In other words, the annual instalments would always be treated as falling due on 28 February regardless of whether the ending year is a leap year or not.

• Usual Quarter Days

  In England the ‘usual quarter days’ in each year are:
  25th March (Lady Day)
  24th June (Midsummer Day)
  29th September (Michaelmas Day)
  25th December (Christmas Day).

  One way of remembering these dates (leaving aside Christmas Day, which is easy to remember) is that the relevant dates are all in the 20s and have the same other number as the number of letters in the month to which they refer. For example, there are five letters in the word ‘March’ and the quarter day in March is the 25th. There are four letters in the word ‘June’ and the quarter day in June is the 24th. And so on.

  Historical Note on Quarter Days

  The “usual quarter days” are all Church festivals: 25th March is Lady Day (the Annunciation); 24th June is Midsummer Day, or the birth of St. John the Baptist; 29th September is Michaelmas Day; and 25th December is Christmas Day.

  Dating by reference to festivals was common in mediaeval times. See, for example, C.R. Cheney (ed.), Handbook of Dates for Students of English History, Royal Historical Society, 1945, page 40:

  “Reference has been made above … to the widespread practice of dating by the nearest festival of the Church. Sometimes this is in addition to the dating by the Roman calendar … At other times one observes in a single class of medieval records, or in a single chronicle, the use of either method indifferently. … But in general it may be said that the method of dating by festivals was early in favour with chroniclers and only in the thirteenth century became usual in dating letters and other documents. It was also used very early for specifying the days of markets and fairs, or those on which rents or other payments were due: of some such we are reminded in modern times by the fact that our English quarter-days still correspond with four Church festivals (Christmas, the Annunciation, the Nativity of St. John the Baptist, and Michaelmas), and other days were similarly used, such as the Conversion of St. Paul and the feast of St. James the Apostle. (The [traditional] Scottish quarter-days are the Purification, or Candlemas (2 February), Whit-Sunday (fixed at 15 May), Lammas (1 August) and Martinmas (11 November)). Hocktide, the second Monday and Tuesday after Easter, was a movable feast often specified for the payment of rents.“

  Even within surviving law reports, there are reported cases going back to the beginning of the seventeenth century in which the usual quarter days are referred to as being “usual” (see, for example, Wm. Clun’s Case, 10 Co. Rep. 126b).

  The Annunciation (25th March) used to be the first day of the year before the reformation of the English calendar by the Calendar (New Style) Act 1750. With the start of the new year being a natural choice for the payment of rent, it is likely that the other festivals became usual merely because they were at convenient intervals of roughly one quarter each.

  The English calendar was fundamentally restructured by the Calendar (New Style) Act 1750, 24 George 2, c. 23 (as amended by the Calendar Act 1751, 25 George 2, c. 30). The 1750 Act was entitled “An Act for regulating the Commencement of the Year, and for correcting the Calendar now in Use“. Section I of that Act provided that:

  “… in and throughout all his Majesty’s Dominions and Countries in Europe, Asia, Africa, and America, belonging or subject to the Crown of Great Britain, the said Supputation, according to which the Year of our Lord beginneth on the twenty-fifth Day of March, shall not be made use of from and after the last Day of December 1751;
  and that the first Day of January next following the said last Day of December shall be reckoned, taken, deemed and accounted to be the first Day of the Year of our Lord 1752;
  and the first Day of January, which shall happen next after the said first Day of January 1752, shall be reckoned, taken, deemed and accounted to be the first Day of the Year of our Lord 1753;
  and so on, from Time to Time, the first Day of January in every Year, which shall happen in Time to come, shall be reckoned, taken, deemed and accounted to be the first Day of the Year;
  and that each new Year shall accordingly commence, and begin to be reckoned, from the first Day of every such Month of January next preceding the twenty-fifth Day of March, on which such Year would, according to the present Supputation, have begun or commenced …“

  Section VI of that Act went on to provide:

  “That nothing in this present Act contained shall extend, or be construed to extend, to accelerate or anticipate the Time of Payment of any Rent or Rents, Annuity or Annuities, or Sum or Sums of Money whatsoever, which shall become payable by Virtue or in Consequence of any Custom, Usage, Lease, Deed, Writing, Bond, Note, Contract or other Agreement whatsoever, now subsisting, or which shall be made, signed, sealed or entered into, at any Time before the said fourteenth Day of September, or which shall become payable by virtue of any Act or Acts of Parliament now in Force, or which shall be made before the Said fourteenth Day of September, or the Time of doing any Matter or Thing directed or required by any such Act or Acts of Parliament to be done in relation thereto …“

  The old practice was therefore preserved in spite of the calendar being altered so that the first day of the year was now 1st January rather than 25th March. This practice has persisted to date so that even many twenty-first century commercial leases are drafted so that rent is payable on the usual quarter days. Some other jurisdictions, including Scotland, have altered the usual quarter days by statute so that they fall on days which appear more sensible and memorable to modern minds, but no such thing has been done in England.

• Legal Notices

  Disclaimer

  Every effort has been made to ensure that this calculator functions correctly, and members of Chambers themselves use it. However, no liability can be accepted for any errors which might arise in its operation, and use is entirely at the user’s risk.

  Copyright

  Copyright in this calculator vests in the Head of Chambers for the time being of New Square Chambers. However, this calculator is freeware and may be used on this website without charge for any commercial or non-commercial purpose.

  Feedback

  If you have any comments (whether good or bad) on this calculator or if you spot any errors, New Square Chambers would be only too pleased to hear about them. Please e-mail us. Thank you.

  © Copyright New Square Chambers 2026 | Head of Chambers at New Square Chambers | version 3.1