Built by operators,
for operators
CalStack is a network of free professional calculators built for people who run real businesses. Every tool includes industry benchmarks so you get context with your number, not just a calculation.
Why CalStack exists
Most online calculators give you a number. CalStack gives you a decision. The difference is context: knowing whether your food cost percentage is healthy, warning, or critical for your specific restaurant type changes what you do next.
The idea came from seeing operators make avoidable mistakes because they lacked access to the same benchmarking data that larger, better-resourced businesses use as standard practice. CalStack makes that data freely accessible to every operator, regardless of size.
What we build
Every calculator on CalStack is built around three principles:
- Hyper-specificTools built for a specific industry and use case, not generic formulas that apply to everything and nothing.
- Benchmark-drivenEvery result is contextualised against real industry data so you know what your number means.
- Free foreverThe core calculators are free, always. No account required, no limits on use.
Editorial standards
All content on CalStack is written and reviewed to a consistent editorial standard. Benchmarks are sourced from primary industry bodies: the National Restaurant Association, the Uniform System of Accounts for Restaurants, Cornell University's Center for Hospitality Research, and equivalent authorities in each industry category.
Fact-checking process: Every calculator page is reviewed for mathematical accuracy, benchmark currency, and content clarity before publication. Sources are cited with direct links wherever available. If you find an error or an outdated benchmark, contact us and we will review and correct within 48 hours.
Who is behind CalStack
CalStack is built and maintained by Tim Guruge. Tim's background spans construction estimating, working through material takeoffs, labour cost builds, and subcontractor pricing for residential and light-commercial projects, and running an independent freelance practice, where the exact problems CalStack solves (hourly rate setting, project margin tracking, self-employment tax estimation) came up on every engagement.
That direct exposure to the estimating and pricing gaps that independent operators face is what CalStack is built around. The tools are not generic formula wrappers, each one is designed around the specific inputs and outputs that professionals actually use when pricing work or managing costs.
Research methodology
Every benchmark and reference figure on CalStack is sourced from primary industry bodies and verified before publication. The standard sources by category are:
- ConstructionNational Roofing Contractors Association (NRCA), Asphalt Roofing Manufacturers Association (ARMA), National Association of Home Builders (NAHB), American Concrete Institute (ACI), and AWC span tables for structural lumber.
- RestaurantNational Restaurant Association (NRA), Uniform System of Accounts for Restaurants (USAR), and Cornell University's Center for Hospitality Research for segment-level benchmarks.
- FreelanceIRS Publication 334 and Publication 505 for self-employment tax figures, updated each tax year. Rate benchmarks draw from Bureau of Labor Statistics Occupational Employment data.
Benchmarks are reviewed against primary sources annually, or immediately when a source publishes updated data. If a figure on any page is out of date, the correction process is described below.
CalStack is an independent project. It is not affiliated with any of the industry bodies cited as sources.
Contact
For benchmark corrections, calculator requests, partnership enquiries, or anything else: email hello@calstack.pro
CalStack Editorial
Every calculator page is reviewed for mathematical accuracy, benchmark accuracy, and content clarity before publication. Benchmarks are checked against primary industry sources annually.