Mortar Mix Calculator – Type N, S & M Yields

This tool applies the formula Type N = 1 : 1 : 6 (cement : lime : sand); S = 1 : 0.5 : 4.5; M = 1 : 0.25 : 3 directly to the measurements you enter, so the result is an exact quantity rather than a rough guess. Because mortar mix is priced and delivered per unit - cubic meters, square meters, bags or tonnes - a small measurement error multiplies across the entire order, which is why the calculation is worth doing properly. Worked example: One 50 kg bag + 0.11 m³ lime + 0.24 m³ sand gives 0.29 m³ of Type N mortar. One note from practice: Stronger is not better: Type M on soft brick cracks the units. Enter the mortar type and batch size, check the totals, then round up to the nearest whole bag, sheet or roll before you place the order.

1. 1

   Take dimensions

   Note the mortar type and batch size for the area you are covering or filling.

2. 2

   Run the calculation

   The calculator applies Type N = 1 : 1 : 6 (cement : lime : sand); S = 1 : 0.5 : 4.5; M = 1 : 0.25 : 3 the moment you type.

3. 3

   Check the breakdown

   Compare base quantity and waste-adjusted totals side by side.

4. 4

   Plan the purchase

   Use the final figure to price and schedule the delivery.

• Missing lintel allowance

• Mixing mortar too strong or weak

• No allowance for breakage