Ownership and lineage
FormulaDen builds further on the CalculatorAtoZ and UnitsConverters platform. While Sonali was developing the ideas of Visual Calculators viz. Percentage Calculator, Fraction Calculator, EMI Calculator, Average Calculator, Trigonometry Calculator, Combinatorics Calculator, LCM HCF Calculator; Sonali came up with the idea that calculators in the form of LaTeX formulas will help young students learn faster and better. She noticed in most online calculators — they give results but rarely show how the formula works. Her vision was to create a tool where users can see the logic, manipulate the variables, and compute the result, all within a single clear LaTeX layout. This approach helps users learn and calculate simultaneously, fostering both education and precision.
FormulaDen.com is owned by Sonali Khandelwal and developed and maintained by Softusvista, a company known for building user-centric, data-driven, and educational web applications. The same team also built CalculatorAtoZ.com and UnitsConverters.com. Together, these platforms form a complete ecosystem — FormulaDen provides the formulas, CalculatorAtoZ performs the calculations, and UnitsConverters ensures accurate unit conversions.
What makes FormulaDen unique
FormulaDen.com is an innovative platform designed to show formulas in LaTeX format with integrated calculators, allowing users to not only view the formulas but also perform real-time computations within them.
The platform now hosts verified formulas across multiple subjects and disciplines, making it one of the largest online formula repositories in the world. These formulas have powered millions of calculations and continue to serve students, researchers, engineers, and professionals globally.
Scale and coverage
FormulaDen.com sources tried and tested formulas from CalculatorAtoZ.com and UnitsConverters.com.
In addition to on-page computations, FormulaDen.com also offers 900+ free downloadable PDFs containing grouped and structured formula sets — serving as quick revision sheets, academic handbooks, and professional reference guides. These PDFs are designed for offline access, making it easy to study, revise, or refer to formulas without needing an internet connection.
Subjects we cover
Engineering
Mathematics
Physics and Chemistry
Finance
Health
About Sonali Khandelwal — the brain behind FormulaDen.com
Sonali Khandelwal is a product-focused technologist and founder who has worked extensively on building visual, interactive calculators and learning tools for the web. Her work emphasizes clarity, correctness, and usability — making complex topics approachable through step-by-step logic. With a background spanning mathematics, engineering, and data-driven UX, Sonali has helped millions of users learn and compute with confidence.
Before creating FormulaDen.com, Sonali developed the widely used platforms CalculatorAtoZ.com and UnitsConverters.com, both known for their accuracy, reliability, and educational depth. Her vision with FormulaDen.com extends that mission — transforming static formulas into interactive learning tools using LaTeX-powered visual computation.
Sonali holds an MBA in Finance and Marketing and has hands-on experience in accounting, data analysis, reconciliations, and system design. This blend of analytical and practical expertise enables her to bridge the gap between theoretical formulas and real-world applications, making FormulaDen.com a trusted resource for students, educators, and professionals worldwide.
About Softusvista
Softusvista is a reputed software development firm specializing in educational, analytical, and computational tools. The team has deep experience in building systems that combine clean interfaces with precise math and science engines. They have developed and maintained FormulaDen.com end-to-end and also operate long-running platforms like CalculatorAtoZ.com and UnitsConverters.com. Explore more of their work via the Softusvista website and affiliate projects.
Privacy and access
FormulaDen.com respects user privacy and does not store or track any user data. All computations are performed securely in the user’s browser, ensuring 100% privacy and security.
The platform is completely free to use, requires no registration or sign-in, and offers instant access to all formulas and PDFs without restrictions.
Get in touch
It is easy to contact the team via the Contact Form. For more information or collaboration, please visit the Contact page for detailed support.
Contact links
For questions, feedback, or collaboration, use the Contact Form. For detailed support or partnership inquiries, visit the Contact page.