Website Loading Time Budget Calculator
This is a user-defined serial model, not measured browser performance, page load prediction or a network guarantee.
This is a user-defined serial model, not measured browser performance, page load prediction or a network guarantee.
Enter resource rows: name; size; size unit.
B, kB, MB, GB, TB, KiB, MiB, GiB, TiB, bit, kbit, Mbit, Gbit, Kibit, Mibit, Gibit
Enter scenario rows: name; mode; throughput; throughput unit; overhead; budget; time unit. Use forward or budget. Budget is required only in budget mode; write - otherwise.
forward, budget; B/s, kB/s, MB/s, GB/s, TB/s, KiB/s, MiB/s, GiB/s, TiB/s, bit/s, kbit/s, Mbit/s, Gbit/s, Kibit/s, Mibit/s, Gibit/s; ms, s, min, h
Sum of bytes × 8 ÷ effective bits per second + entered overhead. In budget mode: (budget − overhead) × bits per second ÷ 8; floor for whole bytes.
Enter complete non-negative decimals, valid units and a valid model state. Maximum 100 scenarios, 200 resources and 2000 history timestamps per scenario.
A QUICK WALKTHROUGH
How to use this tool
- Enter resource rows: name; size; size unit.
- Enter scenario rows: name; mode; throughput; throughput unit; overhead; budget; time unit. Use forward or budget. Budget is required only in budget mode; write - otherwise.
- Calculate and read every resource and scenario result. Copy or download the same frozen exact report.
Model
This is a user-defined serial model, not measured browser performance, page load prediction or a network guarantee.
Boundary rules
Sum of bytes × 8 ÷ effective bits per second + entered overhead. In budget mode: (budget − overhead) × bits per second ÷ 8; floor for whole bytes.
GOOD TO KNOW
Common questions
Is this an actual page measurement?
No. No page is fetched. Concurrent transfers, rendering, caching and browser scheduling are outside this serial model.
How are units and zero throughput handled?
B is a byte and bit is a bit; SI uses 1000 and IEC uses 1024. Zero bytes at zero throughput require zero transfer time; positive bytes at zero throughput cannot transfer.
Can the budget be negative?
A budget below overhead is infeasible, even for zero bytes. Capacity is shown as an exact fraction and a whole-byte floor.