Mortar & Grout Calculator — m, bags, cost
How to use this calculator
Choose a mode: mortar for brick walls, mortar for block walls, grout for block fill, or custom volume entry. Enter wall dimensions in meters or centimeters and the calculator estimates bags needed.
Mortar Classes — M20 (20 MPa, structural), M10 (10 MPa, general), M5 (5 MPa, interior), M2.5 (2.5 MPa, partition).
Bag Sizes — 25 kg and 40 kg pre-mixed mortar.
Currency — Select EUR, PLN, CZK, SEK, etc.
Saved Calculations
| Time | Mode | Area m² | Vol L | Bags | Weight kg | Cost |
|---|
How to Use This Metric Mortar & Grout Calculator
Choose a mode. Brick Mortar sizes bed and head joints from the selected format (NF, DF, 2DF) and joint thickness. Block Mortar assumes face-shell bedding on 400×200 mm coursing. Block Grout fills cores by block width and fill spacing. Custom takes a known volume in litres from a takeoff. Enter wall length and height in m, cm or mm, set a waste allowance, and you get net volume, volume with waste, bag count, weight and cost in your chosen currency. For a full unit count, start with the metric brick wall calculator or the metric block wall calculator, then size mortar and grout here.
Formulas
Bricks/m² = 1 000 000 / [(L+joint)(H+joint)] in mm; mortar/m² = bricks/m² × (bed + head joint) volume. Grout fill (L) = wall area × core volume per m² × fill fraction. Bags = ⌈volume×(1+waste) / bag yield⌉. Bag yield: 40 kg ≈ 20 L mixed, 25 kg ≈ 12 L mixed.
On the jobsite
Mortar classes follow EN 998-2 — M20 for structural and below-grade, M10 for general exterior, M5 above grade, M2.5 for interior partitions. Grout follows EN 206 consistency for core fill. 2025 EU pricing: 25 kg pre-mixed mortar runs €5–9 per bag, 40 kg bags €7–12, and coarse grout 25 kg €8–14 (PLN/CZK/SEK price similar after FX). The number-one estimator mistake is undercounting head joints — bed joints alone come up about 40% short, so this calculator includes both. NF brick (240×115×71 mm) with 12 mm joints needs roughly 30–40 L of mortar per m²; a 200 mm block wall uses about 8–10 L per m². Allow 10–15% waste for mortar and 5–10% for grout, more on pilasters and arches. Downstream, estimate the retaining wall or stone veneer bed, and for poured cores or bond beams compare with the concrete bag calculator. Need imperial units? Use the imperial mortar & grout calculator.
FAQ
How much mortar per m² of brickwork? About 30–40 L per m² of single-leaf NF brick with 12 mm joints — roughly 2–3 25 kg bags. Is waste included? Yes — bag count uses the volume with your waste allowance and rounds up to whole bags. Mortar vs. grout? Mortar bonds units at the joints; grout is a fluid mix poured into block cores around reinforcement — use the Block Grout mode.
