First Contentful Paint Calculator
Estimate FCP by summing network, server, and rendering times with grading against Lighthouse thresholds.
How to Use the First Contentful Paint Calculator
- Enter server response time in milliseconds.
- Add redirect, DNS, TCP, and TLS times.
- Enter first render time.
- Click Calculate for FCP estimate and grade.
Use Cases
- •Web performance optimization
- •Lighthouse score improvement
- •Server-side performance analysis
Formula
FCP = Redirects + DNS + TCP + TLS + Server Response + Render
Frequently Asked Questions
How accurate is this calculator?
Results are based on standard industry formulas and are suitable for preliminary estimates.
What units are used?
Standard IT units (requests/sec, ms, %, USD) are used unless otherwise noted.
Is it free?
Yes, all calculators are completely free.