Rebota Works · Calculators

Free Construction Calculators — IS Standard

36+ professional-grade calculators built for Indian contractors, engineers, and MSMEs. Every result benchmarked against Indian industry averages from CPWD, BIS, and NBO data.

36+

Calculators

Categories

Standard Aligned

Free

No Signup

Cash Flow & Profit MSME Act 2006

Construction Finance Cost Calculator — Project Loan Interest & Delay Cost

Calculate planned vs. actual construction finance interest cost, and the additional financing cost …

Use Calculator →

Construction Project Cash Flow Calculator

Project your cash flow across billing, retention and payment cycles.

Use Calculator →

Hidden Profit Loss Calculator — Where Contractors Lose Margin

A single calculator estimating total hidden profit leakage across material, labour, equipment and b…

Use Calculator →

MSME Delayed Payment Interest Calculator

Calculate interest owed under the MSME Act for delayed client payments.

Use Calculator →

Project Profit Calculator for Contractors

Calculate real project profit after hidden cost leakage.

Use Calculator →

Retention Money Calculator for Construction Contracts

Calculate retention money withheld and its cash flow impact.

Use Calculator →

Working Capital Calculator for Construction Contractors

Calculate working capital required per project size and cycle.

Use Calculator →

Equipment & Fuel IS 4681

Construction Equipment Fuel Cost Calculator

Calculate fuel cost leakage across owned and hired machinery.

Use Calculator →

Equipment Cost Calculator — Owned vs Hired

Compare true owned vs hired equipment cost per project.

Use Calculator →

Equipment Depreciation Calculator for Contractors

Calculate depreciation on owned construction equipment the way Indian contractors actually use it.

Use Calculator →

Equipment Utilization Calculator

Find out how much idle equipment time is costing your project.

Use Calculator →

OEE Calculator — Overall Equipment Effectiveness for Manufacturing

Calculate OEE (Availability x Performance x Quality) for any production line or machine, per the IS…

Use Calculator →

GST & Tax CGST Act 2017

GST Calculator — Construction Works Contract & Material Supply

Calculate GST for construction works contracts (12%/18%), material supply, and services with CGST/S…

Use Calculator →

GST Input Tax Credit (ITC) Calculator for Contractors

Calculate GST ITC you may be leaving unclaimed on construction purchases.

Use Calculator →

GST Late Payment Interest Calculator

Calculate interest liability on delayed GST payments.

Use Calculator →

TDS Calculator — Section 194C, 194J, 194I for Contractors

Calculate TDS on contractor payments (194C), professional fees (194J), and rent (194I) with PAN and…

Use Calculator →

Labour & Attendance BOCW, CLRA

Attendance Leakage Calculator — Ghost Wages Estimator

Estimate wages lost to attendance leakage and buddy punching on site.

Use Calculator →

EPF / ESIC Calculator — Employee & Employer Contribution

Calculate EPF (12%) and ESIC (employer 3.25% / employee 0.75%) contributions for construction worke…

Use Calculator →

Labour Productivity Calculator for Construction Sites

Measure labour output against Indian construction productivity benchmarks.

Use Calculator →

Overtime Cost Calculator for Construction Labour

Calculate true overtime cost across your workforce.

Use Calculator →

Material & Wastage IS 383, IS 1786

Cement Bag Calculator — Concrete, Plaster & Brickwork Mortar

Calculate exact cement bags needed for concrete, plastering, and brickwork mortar per IS 456:2000 a…

Use Calculator →

Cement Wastage Calculator — Find Your Hidden Material Loss

Calculate cement wastage on your site against Indian industry benchmarks and see the annual profit …

Use Calculator →

Concrete Volume Calculator — Cement, Sand, Aggregate Quantity (IS 10262)

Calculate concrete volume and exact cement, sand, aggregate, and water quantities for any grade (M1…

Use Calculator →

Development Length Calculator — IS 456:2000 Clause 26.2.1

Calculate reinforcement development length (Ld) per IS 456:2000 for tension and compression bars, a…

Use Calculator →

Material Price Escalation Calculator

Track how material price movement is eating into your project margins.

Use Calculator →

Raw Material Yield Calculator — Good Output vs. Theoretical Standard

Calculate raw material yield (good output vs. theoretical output), scrap rate, and the material-cos…

Use Calculator →

Rework Cost Calculator for Construction Projects

Calculate the true cost of rework and quality rejection on site.

Use Calculator →

Steel Consumption Calculator for Construction Projects

Estimate steel consumption and wastage per BOQ against Indian benchmark rates.

Use Calculator →

Steel Weight Calculator — TMT Bar Weight per Meter (IS 1786)

Calculate TMT steel bar weight per IS 1786:2008 unit weight formula for any diameter 6mm to 32mm, w…

Use Calculator →

Tendering & Bidding GFR, CPWD DSR

Tender Margin Calculator — Bid Pricing for Contractors

Calculate safe tender margins accounting for real execution risk.

Use Calculator →

Engineering & Finance Tools IS 2502, IS 456

Bar Bending Schedule (BBS) Calculator

The most complete BBS calculator for Indian construction — all IS 2502 shapes, IS 456 development l…

Use Calculator →

CAGR Calculator

Find the compound annual growth rate between a starting and ending value over any period, with year…

Use Calculator →

Compound Interest Calculator

Principal, recurring contributions, contribution step-up, compounding frequency, fees, inflation an…

Use Calculator →

Inflation-Adjusted Returns Calculator

Find the real (inflation-adjusted) rate of return via the Fisher equation, and what a delayed payme…

Use Calculator →

NPV & IRR Calculator

Enter any series of cash flows and a discount rate to get Net Present Value, then find the Internal…

Use Calculator →

XIRR Calculator

Enter dated, irregularly-spaced cash flows (staggered payments, equipment financing, retention rele…

Use Calculator →

Want these numbers tracked automatically instead of calculated by hand? Rebota is a business platform →

Why engineers use these calculators

Every calculator on this page is built to Indian construction standards (IS codes, CPWD DSR, BOCW) and benchmarked against real industry averages — not generic formulas. Results are meant to be checked against a real site before use, but they get you a fast, defensible starting number.

Why Rebota Works?

100% Free

No signup required. Always free.

IS Standard Aligned

References from real IS codes.

Verified & Trusted

Accurate formulas and real-world tested.

Made for Professionals

Engineers, contractors & construction teams.

Learn more about Rebota Works →

Save & Access Anywhere

Save your favorite tools & resources

Smart Search (Ctrl+K)

Find what you need in seconds

Community Support

Ask questions & get real answers

Regularly Updated

New tools, templates & guides added