How ProCalc’s Price Guide Stays Accurate

Even the most seasoned industry professionals finding pricing tough in today’s market. So how accurate is ProCalc and how can you verify it?


ProCalc’s Algorithm is Currently 93% Accurate (March 2023)

That is, 93% of the time, builders actual estimated construction costs are within ProCalc’s range (as at March 2022).

So, if you calculate 100 projects, 93 of them will be within ProCalc’s forecast range. Seven will not. We further improve ProCalc’s accuracy with all the project data that comes in from builders, architects and designers costing real projects.

How ProCalc Delivers Accurate Results

In 2020, we started by creating the mother of all builders’ spreadsheets, factoring in every possible variable that effects builders pricing.

Materials, labour, timeframes, locations, regulations, contracts, client preferences, detail of finish, tendering process….and so much more.

Once we’d created the algorithm, we then tested it with hundreds and hundreds of real builders’ projects to make it more and more accurate.

That is, we used builders costing methods to create a real-world algorithm that was based on how builders cost and construct various residential projects.

The ProCalc available today has been calibrated with these projects on a monthly basis. We take the results of real designs and their tender responses and feed them back into our modelling.

ProCalc also factors in latest industry data from HIA and ABS.

Our goal is to get 94% accuracy, then 95%…and so on.

Thousands of projects have now been fed into the algorithm, so you have the confidence that the modelling is tried and tested by industry professionals who went before you.

Book A Free ProCalc Trial Now

How Does ProCalc deal with Market Changes & Supplier Cost Increases?

Builders constantly have to update their prices due to materials and labour price increases.

Moving prices are a fact of life, so the ProCalc algorithm is updated every 30 days based on real builders pricing.

We review builders pricing on real projects throughout Australia to ensure we stay right up to date with market price changes.

ProCalc’s algorithm is formerly updated every 30 days so you have the most accurate price guide.

Builders Margins Vary Between Builders

We understand that builders charge different margins depending on their team structure, type of work, location, business strategy, operating expenses and so much more.

So, ProCalc provides a range that covers both low and high margins (which also aligns with traditional tender differences from the lowest to highest).

That is, ProCalc allows for all types of builders’ estimates.

How to Test ProCalc’s Accuracy

The fastest and easiest way to test ProCalc’s accuracy is to run through an existing project you’ve costed during your free trial period.

You get to verify ProCalc’s accuracy at no cost. If you like it, subscribe.

Book A Free ProCalc Trial Now

Author Richard Armstrong is a project manager & former registered builder who specialises residential construction pricing. With post-grad property qualifications and over 15 years’ design & construct experience, he is the Founding Director of ProCalc – Professional Construction Estimator. Free trial at

A Client Who Wants to "Think About It" Actually Needs Help - Here's What to Do

We’ve all heard those crushing words from clients…” We’d like to think about it”. After weeks of empathy, inspiration and perspiration, they’ve become stuck – and indecisive. Here’s how to help them move forward…

Costing Concepts at the Right Time Supports Great Design & Reduces Budget Stress

We surveyed architects and designers to see when and how they use ProCalc in their design process to improve their design outcomes and minimise budget stress. See how others approach budget management.

The Earlier a Client Grasps Costs, The More Likely They are to Build – Here’s Why

When clients receive their first cost guide they respond in one of four ways (hint: three of them are positive). See how early, reliable information can help you can guide clients to a smooth, constructed landing.

Be the Informed Sherpa, Not the Fearful Professional – How & Why

With volatile price increases, many design practitioners have become reluctant – even fearful –advising clients. See how to provide informed, low risk advice to clients that builds relationships.

Ditch the Crystal Ball for Construction Pricing – Here’s Why

Clients always want to understand construction costs for the future to reduce surprises. Here’s why you should be wary of future forecasts.

One Simple Email Can Dial Down Budget Stress –Here’s how...

Historically, re-setting client budget expectations has been fraught with challenges and risks for design professionals. See how one simple email template can make your life easier…