What counts as a reasonable retainer fee depends on the industry, the professional's experience, and what's actually being delivered. For design work specifically, a retainer should cover the designer's time for a set period and reflect what that time is genuinely worth, without making the client feel like they're getting robbed.

For graphic and brand designers, monthly retainers typically run between $1,000 and $5,000. Interior designers usually charge project-based retainers in the $1,500 to $5,000 range. UX/UI and digital product designers tend to charge more, often $3,000 to $10,000 per month, depending on hours and deliverables.

A simple way to set a retainer: estimate your monthly hours, multiply by your hourly rate, then add 10 to 15% for admin time and the inevitable scope creep that sneaks in. If you charge $100 per hour and expect to work 20 hours a month, your retainer should land somewhere between $2,000 and $2,300. It's not complicated math, but a lot of designers skip it and end up undercharging.

From the client side, a retainer feels reasonable when the scope is clear, the rate matches what the market charges, and the arrangement is cheaper than hiring someone full-time or constantly negotiating project fees. Clients on retainer also tend to get faster turnaround and consistent availability, which has real value.

From the designer's side, the retainer needs to actually cover the work. Retainers set too low breed resentment and, eventually, worse work. Retainers set too high push good clients away. Neither outcome is good.

Before signing anything, both sides should get clear on a few specifics: do unused hours roll over? Is the retainer refundable if the relationship ends early? How are overages billed? These aren't fun conversations, but skipping them causes most of the disputes that blow up retainer relationships later.

A reasonable retainer, in the end, is one built on actual numbers, written down, and agreed to before anyone does a single hour of work.