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The reference desk for every estimate.

Formula sheet, unit conversions, common errors, final tender checklists, glossary and primary South African procurement sources.

Formula sheet80+ termsFinal checklistsOfficial references
Current-law and live-tender rule

This training was reviewed on 05 August 2026. Procurement and tax rules continue to change, including implementation work around the Public Procurement Act 28 of 2024. For every real bid, use the law and tender instructions applicable on its advertisement date, check all addenda, and verify current SARS, Treasury, CIDB and sector requirements.

Quick reference

Estimator’s formula sheet

Every formula is only as reliable as its scope, unit and source data. State denominators and percentage bases.

Resource consumptionGross resource = Net requirement × (1 + justified loss %)Use layout, laps, yield or pack rounding where more accurate.
ProductionOutput = Completed quantity ÷ Productive timeUse the same time basis in cost and output.
Labour intensityLabour-hours/unit = Crew size × Productive hours ÷ OutputInclude paid necessary non-productive time in achievable output.
Plant cyclesOutput/hour = Payload × (60 ÷ Cycle minutes) × EfficiencyBalance linked plant; the bottleneck controls.
m² to m³Volume = Area × Thickness in metres100 mm = 0.100 m, not 0.010 m.
Mass and densityMass = Volume × DensityKeep kg/m³ and t/m³ conversions consistent.
PreliminariesTotal = Fixed + (Monthly × Months) + Value-relatedBuild from project obligations and recovery rules.
Expected monetary valueEMV = Probability × Residual cost impactAlso test the full impact and correlated downside.
Markup priceSelling price = Cost × (1 + Markup %)Markup denominator is cost.
Target-margin priceSelling price = Cost ÷ (1 − Margin %)Margin denominator is selling price.
Cash financeFinance ≈ Balance × Annual rate × Days ÷ 365Add facility fees; full cash flow remains necessary.
80/20 price pointsPs = 80 × [1 − (Pt − Pmin) ÷ Pmin]Use the live tender and current applicable rules.
Measurement

Unit conversion controls

Write the unit beside every input. If units do not cancel to the BOQ unit, the calculation is incomplete.

From To Method Example Common error
mm m ÷ 1,000 75 mm = 0.075 m Dividing by 100
m² + thickness m³ Area × thickness (m) 250 m² × 0.1 m = 25 m³ Using thickness in mm
m³ t × density t/m³ 5 m³ × 2.4 t/m³ = 12 t Using kg density without ÷ 1,000
litre m³ ÷ 1,000 250 L = 0.25 m³ Confusing litre and kilolitre
kg tonne ÷ 1,000 3,500 kg = 3.5 t Rate remains per kg
Monthly Hourly ÷ actual paid/productive hours Use roster/calendar Assuming 160 hours universally
Pack Installed unit Ceiling(net ÷ coverage) × pack cost ÷ net Small orders affected by pack rounding Buying fractional packs
Loose volume Pay volume Use stated state conversion 1.22 loose/bank factor Applying factor in wrong direction
Final controls

Tender review checklists

Ticking a box is not evidence. The reviewer must locate the supporting document or calculation.

Error prevention

Twenty mistakes that destroy tender prices

These errors recur across goods, services and works tenders.

No. Error Consequence Control
1 Pricing only the BOQ description Contract and specification obligations omitted Cross-reference requirement map
2 Supplier quote treated as final rate Delivery, installation and warranty omitted Normalise complete delivered scope
3 Wage used as labour cost Employment burden and relief lost Build burdened productive rate
4 Paid hours treated as productive Labour unit rate understated Use observed achievable output
5 Theoretical plant output used alone Fleet and downtime understated Cycle and bottleneck analysis
6 Blanket waste percentage Loss over- or understated Layout, yield and pack calculation
7 Preliminaries copied as a % Duration and site duties missed Fixed/time/value schedule
8 Overhead confused with profit Business cost not recovered Separate cost and return layers
9 Markup called margin Profit lower than intended Use algebra and final margin check
10 Risk included several times Uncompetitive price Risk register and duplication review
11 Known scope put in contingency Unclear and uncontrolled estimate Move known cost to base
12 VAT duplicated or misrepresented Wrong total / compliance issue Verify status and quote basis
13 Old quote used without adjustment Price validity exposure Date, validity and escalation control
14 Optimistic framework quantity Fixed cost unrecovered Volume sensitivity / separate setup
15 No cash-flow forecast Profitable tender cannot be funded Monthly cash and facility review
16 m, m² and m³ mixed Major conversion error Unit scan and dimensional check
17 Addendum not flowed into estimate Wrong scope or non-responsive bid Addendum register and version lock
18 Client budget forced into BOQ Hidden loss and arbitrary rates Independent build-up, then target review
19 Late uncontrolled edit Forms and totals disagree Price freeze and one final owner
20 No award handover Delivery team misses assumptions Estimate-to-contract handover pack
Language

Tender and estimating glossary

Search the terms used throughout the course. The live tender or contract may define a term differently.

Primary references

Official South African sources

Use these primary sources to verify current procurement, forms, contractor and tax information.

eTender Publication PortalCurrent public-sector tender opportunities and procurement data
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Central Supplier DatabaseSupplier registration and information maintenance
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National Treasury standard bidding formsCurrent SBD forms published by OCPO
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Preferential Procurement Regulations, 2022Official Gazette PDF; check transitional applicability
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PPR 2022 implementation guideNational Treasury implementation guidance
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Public Procurement Act 28 of 2024Enacted Act; verify commencement and transitional position
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Draft General Public Procurement Regulations 2026Draft consultation material—not final law
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CIDB Standard for UniformityEngineering and construction works procurement standard
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CIDB Register of ContractorsGrading overview and current tender value information
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SARS VAT registrationCurrent compulsory and voluntary registration information
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SARS VAT overviewCurrent standard rate and vendor information
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National Treasury General Conditions of ContractGeneral conditions used with applicable public procurement documents
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