Retainer Maths

The problem in detail

When a client asks for a block of guaranteed hours, a monthly retainer, or a fixed price for a long project, freelancers have no reliable way to decide what discount is justified or how much scope creep they're absorbing. They fall back on their standard hourly rate, invent a number, or ask strangers on Reddit — and only find out months later that they underpriced or ate unpaid extra work.

Proposed product

A deal modeller for a single engagement. You enter the shape of the offer (hours per month, length of commitment, payment terms, whether hours roll over, your current rate and realistic billable capacity). It returns an effective hourly rate after the discount, the opportunity cost of the capacity you're locking up, a break-even scope-creep threshold (how many unbilled extra hours turn the deal into a loss), and a plain-English recommended floor rate. Each model generates a one-page summary with the contract clauses that protect the assumptions — minimum commitment, hour expiry, overage rate, scope-change trigger — ready to paste into a proposal.

Why now

The evidence shows no recent trigger — free retainer calculators already exist (retainerbase.ai, freelancepricing.com, calculators-lab.com) and the underlying complaint about retainer scope creep is long-standing, documented in trade press and vendor guides. Treat this as a persistent problem that nobody has solved well on the economics side (opportunity cost, break-even creep, contract clauses) rather than a newly opened window.

Smallest useful version

A single-page web calculator covering the three most common structures (guaranteed-hour block with discount, monthly retainer, multi-month fixed price), with no account needed, that outputs effective rate, break-even creep hours, and a copyable overage/scope clause. Distributed in the freelance subreddits where people currently post 'what should I charge for this?' and validated by whether they paste their numbers in and share the result.

Potential ways to charge

• Free calculator — £0: all three deal structures, effective rate and break-even creep hours, no signup (anchored to the free competitor tools found at retainerbase.ai and freelancepricing.com, which set the price floor at zero)
• Saved models and PDF one-pager — £6 per month: store engagements, compare offers side by side, branded one-page summary for the client (typical for comparable solo-freelancer tools; evidence has no price)
• Clause library and proposal pack — £39 one-off: full set of paste-ready minimum-commitment, hour-expiry, overage and scope-trigger clauses with guidance (anchored below the $97 'Strategic Pricing for Freelancers' ebook seen on Gumroad)
• Pricing review with a human — £75 per engagement: a reviewed model and recommended floor for a specific client offer (anchored to the ~$30/hour-and-up pricing consultants listed on Upwork, priced for a multi-hour review)

Routes to early customers

• Freelance subreddits and Discords where 'what should I charge for this retainer?' posts already appear — the distribution channel named in the MVP
• Organic search for 'how to price a retainer', the same intent the vendor guides from Harpoon, Bonsai, Plutio and Moxie are chasing (evidence 5 infers steady demand but gives no volume figures)
• Freelance newsletters and trade outlets covering the working life of creatives, of the kind that published the Digiday retainer confessional
• Partnerships or affiliate placement with invoicing and contract tools that already publish retainer guides but offer no economics modelling

Main risks

• Several free calculators already cover retainer fees, hour limits, overage multipliers and rollover, so the paid layer must rest entirely on the untested claim that opportunity cost, break-even creep and clause output are what users miss (evidence 1 and 6).
• The riskiest assumption stands untested: freelancers may treat pricing as a judgement call and ignore a calculator's number at the moment of negotiation.
• No evidence was found of anyone paying to model a single retainer offer; the paid pricing demand observed on Upwork was businesses buying product and SaaS pricing strategy, not solo freelancers (evidence 4).
• The headline loss figure ($2,000–$5,000 of unpaid work a year) is a vendor's own estimate on a site selling scope-creep tooling, not primary survey data, so the size of the pain is soft.
• Free-tool SEO is crowded and dominated by funded vendors using calculators as lead magnets; a standalone tool may never rank or may be copied within weeks.

Questions to test first

• Post the bare calculator in two or three freelance subreddits in reply to live 'what should I charge?' threads and count how many people paste their own numbers back — the direct test of the riskiest assumption.
• Interview 10 freelancers who have signed a retainer in the last year: ask what number they used, whether they computed anything, and whether they would have changed terms if shown a break-even creep figure.
• Run the existing free calculators and list exactly what they do and do not output, then show that gap to the same 10 freelancers to see if they recognise it as a problem.
• Put the £39 clause pack behind a 'buy' button that records intent before anything is built, and measure click-through from free calculator users.
• Check search demand for 'retainer calculator' and 'how to price a retainer' against the existing ranking tools before committing to SEO as the channel.

Evidence and sources

The sources this assessment is based on. Evidence level: Indicative, counted from these sources as described in how ideas are assessed. Findings are what a source shows; anything the research only inferred is marked as an inference.

Research findings

• SupportsIndustry statistics roundup page

  Shows: quantified-problem-cost

  A scope-creep statistics roundup (page age ~215 days at retrieval) cites PMI data that 52% of projects experience scope creep and estimates individual freelancers absorb roughly $2,000–$5,000 of unpaid work per year, assuming 8–12 projects with 15–25% scope overrun. This is a non-community, quantified framing of exactly the loss the 'break-even scope-creep threshold' feature targets. Caveat: the freelancer-specific dollar figure is the site's own estimate, not primary survey data, and the site sells scope-creep tooling.

• SupportsTrade press interview (Digiday 'Confessions' series)

  Shows: third-party-reporting-on-problem

  Digiday's anonymous confessional with a freelance creative describes scope creep as a bigger issue specifically when on retainer, with clients adding 'can you just throw this in' requests on top of agreed work. Independent trade-press corroboration (not a forum thread) that retainer structures are where freelancers absorb unbilled work — the exact scenario the modeller prices.

• ContextFreelance marketplace category/job listings

  Shows: paid-demand-for-manual-equivalent

  Upwork runs a pricing-strategy consulting category (4.8/5 from 157 client reviews, hourly rates from ~$30) and lists ~74 open 'Pricing' jobs, and a $97 'Strategic Pricing for Freelancers' ebook sells on Gumroad. People do pay for pricing help. Weak as direct support, though: the visible Upwork demand is businesses buying product/SaaS pricing strategy, not solo freelancers paying someone to model a retainer offer — I found no posting of the latter.

• Supports · inferenceVendor blog / freelance tooling content

  Shows: customer-segment-validation

  Multiple independent freelance-tooling vendors (Harpoon, Bonsai, Plutio, Moxie, managerlist.com) publish retainer-and-scope-creep guides naming the same failure modes: vague scope, unlimited-access expectations, inability to raise the fee mid-term. Bonsai notes retainers make it hard to increase earnings with the same client. The volume of SEO content from tool vendors is an inference that there is steady organic search demand from freelancers for 'how to price a retainer', which is the acquisition channel this product would need.

• Weakens the caseVendor tool pages / competitor calculators

  Shows: existing-solution-saturation

  A free 'Freelance Retainer Package Calculator' already covers much of the proposed feature set: flat-rate retainer fees, monthly hour limits, overage billing multipliers and rollover handling. Similar free tools exist at retainerbase.ai/tools/retainer-calculator, freelancepricing.com (advertising 15+ free calculators incl. retainers, utilization and profitability, no signup) and calculators-lab.com/freelance. Page age at retrieval indicated roughly 110 days for the retainer package tool and ~47 days for freelancepricing.com. This is a crowded free-tool category, so differentiation would have to rest on the opportunity-cost/break-even-scope-creep modelling and the paste-ready contract clauses rather than the rate math itself.

Where the problem was reported

Public posts in which people described this problem, grouped into one problem before research began.

• How to professionally present invoice and work performed? · r/smallbusiness · 2 October 2026
• Can't bill by the hour. Is it a cultural thing? · r/freelance · 11 December 2019
• Client looking for "bulk" hourly pricing · r/freelance · 12 July 2017

Looked for, not found

• No product review, support ticket, issue-tracker item or keyword-volume dataset surfaced showing users of existing retainer calculators complaining that the tools fail to model opportunity cost, hour expiry or break-even scope creep — the specific gap this product claims. Without that, the differentiation claim versus the several free calculators found remains untested, as does willingness to pay for a one-engagement modeller plus clause output.