Plan the work
Carry the estimate into the job plan.
The useful result is not just the number. It should support owners, programme assumptions and delivery readiness.
Workflow
Work quantity
Project Planning
Project Duration Calculator.
Estimate project duration from work quantity, productivity and crew count. Free online tool for UK construction and trade teams.
Connected calculator
Live estimate
Use the result as a planning estimate, then turn it into tasks, templates, evidence and delivery records.4Inputs
2Results
3Trade tags
Estimate In Product
Put the calculation beside the workflow it informs.
Project Duration Calculator is a quick way to test the number. Zektrx gives that number a route into planning, materials, evidence and reporting once the work starts moving.
1
Plan the work
Work quantity
2
Check materials
Estimated duration
3
Report the decision
Project Management
Check materials
Turn quantities into stock and purchase context.
Material estimates can connect to stock checks, reservations, purchasing notes and job-linked records.
Workflow
Estimated duration
Report the decision
Keep assumptions visible after the calculation.
Saved outputs can support reports, handover packs, client review and repeatable estimating habits.
Workflow
Project Management
units
units/day
crews
%
Instant Results
Estimated duration
5.5days
Duration including non-working allowance.
Net working days
5.0days
Duration before allowance.
Estimate To Evidence
Make the result useful beyond the screen.
A calculator result is most useful when it feeds the job plan, material checks and team briefing that follow the estimate.
Measure the work
Use the estimate as a planning input for scope, labour, equipment and site readiness.
Plan materials
Turn quantities into stock checks, purchasing notes and job-linked material records.
Brief delivery
Give teams the assumptions, limits and checks behind the number before work starts.
Explanation
What this calculates
The calculator divides total work by daily crew output, then applies an allowance for non-working time.
Formula
Days = quantity / (productivity x crews) x (1 + non-working %)
Inputs are validated on screen and converted where unit options are available.
Worked Example
Example result
1,000 units at 100 units/day with 2 crews and 10% allowance gives 5.5 days.
Knowledge Journey
Learn, use, then automate.
1. Learn
GuideJob planning
Construction project management software guide
A practical guide to construction project management software for contractors managing jobs, actions, documents, RAMS, site evidence and handover.
GuideJob planning
Contractor job planning checklist
A practical job planning checklist for contractors covering scope, people, RAMS, materials, documents, access and completion evidence.
GuideJob planning
Job planning software vs spreadsheets for contractors
A practical comparison of contractor job planning software and spreadsheets for readiness, site operations, materials and evidence.
2. Use
CalculatorProductivity
Site Labour Cost Calculator
Estimate labour cost from workers, hours, days, hourly rate and burden allowance. Free online tool for UK construction and trade teams.
CalculatorMaterials
Material Quantity Calculator
Estimate material quantity from area, usage rate and waste allowance. Free online tool for UK construction and trade teams.
CalculatorLifting
Lift Load Weight Calculator
Estimate rectangular load weight from length, width, thickness and density before lifting-plan review. Free online tool for UK construction and trade teams.
3. Automate
Featureproject management
Construction Project Management Software
Plan projects, coordinate teams and keep actions, evidence and reports visible.
Featureprincipal contractors
Principal Contractor Software
Coordinate subcontractors, site evidence, compliance and reporting across projects.
Featurescheduling
Construction Scheduling Software
Coordinate schedules, tasks, dependencies and field readiness.
4. Start
See the principal contractor workspace.
Coordinate subcontractor documents, RAMS, permits, site evidence, actions and audit readiness.
View Principal Contractor WorkflowRelated Content
Connected calculators, templates and workflows.
Related Guides
Keep learning
GuideJob planning
Construction project management software guide
A practical guide to construction project management software for contractors managing jobs, actions, documents, RAMS, site evidence and handover.
GuideJob planning
Contractor job planning checklist
A practical job planning checklist for contractors covering scope, people, RAMS, materials, documents, access and completion evidence.
GuideJob planning
Job planning software vs spreadsheets for contractors
A practical comparison of contractor job planning software and spreadsheets for readiness, site operations, materials and evidence.
Related Calculators
Run the numbers
CalculatorProductivity
Site Labour Cost Calculator
Estimate labour cost from workers, hours, days, hourly rate and burden allowance. Free online tool for UK construction and trade teams.
CalculatorMaterials
Material Quantity Calculator
Estimate material quantity from area, usage rate and waste allowance. Free online tool for UK construction and trade teams.
CalculatorLifting
Lift Load Weight Calculator
Estimate rectangular load weight from length, width, thickness and density before lifting-plan review. Free online tool for UK construction and trade teams.
Related Templates
Document the work
TemplateSite Diaries
Site Diary Template
Record weather, labour, plant, deliveries, progress, delays, visitors, photos and instructions. Free, editable construction template from Zektrx.
TemplateAccident Forms
Accident Report Form
Capture incident details, injuries, witnesses, photos, immediate actions and investigation notes. Free, editable construction template from Zektrx.
TemplateInspection Forms
Site Inspection Form
Capture inspection checks, photos, defects, actions, owners and close-out evidence. Free, editable construction template from Zektrx.
Related Features
Automate the workflow
Featureproject management
Construction Project Management Software
Plan projects, coordinate teams and keep actions, evidence and reports visible.
Featureprincipal contractors
Principal Contractor Software
Coordinate subcontractors, site evidence, compliance and reporting across projects.
Featurescheduling
Construction Scheduling Software
Coordinate schedules, tasks, dependencies and field readiness.
Related Industries
Trade workflows
Industryprincipal contractors
Principal Contractors Software
Principal contractor hubs for subcontractor coordination, RAMS, permits, site records, actions and audit evidence.
Industrysteel fabricators
Steel Fabricators Software
RAMS, drawings, workshop records, install evidence and handover workflows for steel fabricators. One platform for documents, evidence and compliance.
Related Comparisons
Compare options
Comparisongeneric construction management software
Best Construction Management Software
A construction management software buyer guide for teams comparing project controls, site records, documents, compliance and contractor operations.
ComparisonProcore
Zektrx vs Procore
Compare Zektrx with Procore for contractors that need RAMS, site evidence, document control and day-to-day trade operations without enterprise complexity.
ComparisonSpreadsheets
Zektrx vs Spreadsheets
Compare Zektrx with spreadsheet-based construction admin for RAMS, site records, document control, actions, stock and reporting.
Related FAQs
What should on-cost include?
It may include payroll costs, supervision, travel, small tools, welfare or business overhead depending on how you price.
From Site Labour Cost Calculator
Can I use this for tendering?
Use it as an estimating check and reconcile against your commercial pricing rules.
From Site Labour Cost Calculator
Can this calculate any material?
Yes for simple area-based rates such as tiles, boards, membranes or rolls.
From Material Quantity Calculator
Should I round to pack sizes?
Yes. Round final ordering quantities to supplier packs, pallets or roll sizes.
From Material Quantity Calculator
FAQ
Calculator questions.
Does this replace a programme?
No. It is an estimating check. Real programmes need dependencies, access, procurement and resource logic.
Can I use hours instead of units?
Yes, as long as the productivity rate uses the same unit basis.
Next Step
See the principal contractor workspace.
Coordinate subcontractor documents, RAMS, permits, site evidence, actions and audit readiness.