"Add numbers to your resume" is good advice that's hard to follow when you genuinely never had access to exact figures. Here's how to handle it honestly.
Start with what you can reconstruct
Team size, number of projects, frequency of a task, and rough timeframes are usually things you remember even without official reports. "Managed a team of 5" or "ran weekly reports for 3 regional offices" are real numbers, not estimates.
Use a reasonable, labeled estimate when needed
If you genuinely have to estimate, say so honestly in the interview if asked, and keep the estimate conservative. "Reduced response time by approximately 20%, based on team feedback" is defensible. Inventing a precise-sounding number you can't explain is not.
Scale and scope count as numbers too
Not every metric needs to be a percentage. Budget size, number of stakeholders, geographic scope, or volume of requests handled are all quantifying details that work the same way.
When there's truly no number available
It's fine to have a few qualitative bullets. Not every line needs a metric — a resume that's all numbers, some clearly padded, reads worse than one with a healthy mix of measured and well-described impact.