Soil & Amendment Calculators

Site Area
Hardscape, buildings
Use Zones
Logistics
Total Area
Total Weight
tonnes
Truck Loads
loads
Material Cost
$ value
Zone Breakdown
Zone Type% of AreaArea ()Depth (mm)Volume ()
BS 3882:2015 Topsoil Grades: Multipurpose grade for general planting, Specific Use grade for lawns/sports, Low Fertility grade for wildflower/native habitat creation. Recommended depths: lawn 150–300mm, shrub/perennial 300–450mm, tree pit per BS 8545 root volume requirements.
Target Volume
Mix Components
Total Cost
$ value
Estimated Mix pH Range
range
Estimated OM %
% by weight approx
BS 3882:2015 Classification
category
Volume per Component
MaterialRatio %Volume ()Weight (t)Cost ($)
Current & Target pH
Total Amendment Required
kg
Standard Bags Required
bags (25kg/50lb approx)
Estimated Time for Change
months
pH adjustment is most reliably achieved gradually. Large single applications (>0.5kg/m² lime or >0.15kg/m² sulfur) risk shock to soil biology and should be split across multiple applications/seasons. Always retest soil pH 2–3 months after application before further amendment.
Mulch Application
Recommended 75–100mm
Volume
Weight
tonnes
Tipper Loads (8t)
loads
Weed Suppression Rating
rating
Breakdown / Replacement Period
years
Recommended mulch depth: 75–100mm for weed suppression and moisture retention. Avoid mulch directly against stems/trunks (volcano mulching) — leave a collar of 50–100mm clear. Organic mulches improve soil structure over time; mineral mulches (gravel/slate) are permanent but do not improve soil.
Bed Dimensions
Fill Layers
Wall Material
Total Fill Cost
$ value
Wall Perimeter per Bed
m
Total Wall Length
m
Wall Cost
$ value
Grand Total per Bed
$ value
Volume per Layer per Bed
LayerDepth (mm)MaterialVolume () / bedCost / bed ($)
Application Specification
Product N Content
%
Total Product Required
kg
Standard Bags Required
bags (20kg/40lb approx)
N Applied
kg N/ha
P₂O₅ Applied
kg/ha
K₂O Applied
kg/ha
Seasonal Programme Example
SeasonTimingN Rate (kg/ha)Notes
SpringMar-May30-50Boosts early vegetative growth. Avoid before heavy rain.
AutumnSep-Oct15-30Lower N, higher K for root hardiness over winter.
NPK ratios indicate Nitrogen : Phosphorus (as P₂O₅) : Potassium (as K₂O) by weight. Application rate (g/m²) = (N_rate_kg/ha × 100) / N%. Always follow manufacturer instructions and local nutrient management regulations. Avoid application before heavy rainfall to prevent runoff to watercourses.