Claude Bra Size Chart Prompts: 8 Calculator and Fitting Checks

One website offers a size chart. Another offers a calculator. A third asks you to speak to a fitter. You can collect three confident answers before you have established whether they use the same sizing system.

Use Claude bra-size prompts to read the actual retailer’s chart, preserve its sizing system and prepare clear fitting questions. A chart or calculator can supply a starting point according to its own method. Claude cannot confirm physical fit from a label, photograph or generated cover.

Why the chart belongs to the brand

Bravissimo’s US-to-UK sizing page describes its conversion chart as a starting point and notes that brands fit differently. This is why an international shopper should identify the system before comparing letters. Use the current chart attached to the item you are considering, not a conversion recalled from memory.

Claude’s official guidance says it does not generate raster photographs. The prompts here request written analysis, tables or briefs; the separately generated cover is an editorial illustration.

The worked situation here is a shopper with a comfortably fitting current bra who is considering a different retailer. The useful information is the current garment’s brand, model and full size label; the prospective item’s chart; and any observations the shopper wants to discuss. Personal photographs are unnecessary for the written workflows.

Eight prompts that keep sizing evidence visible

1. Identify the system first

Claude, read this retailer’s bra-size page and item chart: [paste with source URL and date]. Identify the stated sizing system, whether it separates band and cup, the units and any measuring instructions. Mark anything not explicit as unclear. Do not infer a system solely from the country of the website or the letters on a label.

Keep the chart name attached to the answer. A retailer may use a sizing convention different from the one you expected.

2. Transcribe the chart without improving it

Turn this supplied bra-size chart into a clean text table. Preserve every stated label, range, unit, note and exception. If an image is unclear, identify the unreadable cell instead of guessing. Do not add sizes, conversions or a new calculation method. Give me a short checklist for verifying the transcription against the original.

This is a useful accessibility task. You still need to check that a tiny symbol or repeated cup letter has not been lost.

3. Separate a calculator’s rules from the result

Explain these actual bra-size calculator instructions: [paste]. List required inputs, measurement method, unit expectations and any limits the provider states. Do not combine it with another retailer’s formula. If an instruction is missing, write the exact question I should ask before using the result.

A calculator result is only meaningful in the context of the method that produced it. More decimal places do not establish better fit.

4. Compare two supplied systems

Compare these two current retailer charts: [paste each source separately]. Identify exact labels that are directly mapped by the supplied information, and mark everything else unmapped. Do not create a universal UK-US-EU conversion. Preserve brand-specific notes and distinguish conversion of a label from a recommendation about physical fit.

If the tables do not provide a conversion, that is the answer. Do not let the model fill a gap with a confident pattern.

5. Prepare a fitter conversation

Write a short message to a bra fitter or retailer. My current garment is [brand, model and full label], my experience is [my own observations], and the item I am considering is [details]. Ask which chart applies and what size or styles they recommend trying. Do not diagnose a fit issue or tell me to ignore discomfort.

Specific observations help: the band shifts during a normal movement, or a strap adjustment does not stay where you put it. Keep the wearer’s wording.

6. Check a sister-size explanation

Read this supplied brand explanation of sister sizing: [paste]. Restate only its stated relationships and system. Explain which points concern cup-volume grouping and which remain physical-fit questions. Do not recommend a replacement size unless the supplied guidance supports it, and do not treat a changed band as the same fit.

Use a current primary explanation, such as Bravissimo’s sister-sizing guide. A relationship within a chart does not mean two garments will feel identical.

7. Create a real fitting record

Make a simple written try-on record for bras I actually try, following these retailer conditions: [paste]. Include brand, model, full size label, fastening setting, my own band and cup observations, strap adjustment, movement and next question for a fitter. Do not score or rank my body. Separate observation from recommendation.

Record the full garment identity. Otherwise a note about one model can accidentally become a rule applied to a different construction.

8. Write an evidence-led shopping checklist

Turn this verified chart information and my fitter’s advice into a concise pre-purchase checklist: [paste]. Include exact item identity, stated system, selected size, included pieces, care, relevant return conditions and unresolved questions. Quote only short necessary labels. Do not guarantee fit, replace professional fitting guidance or fabricate retailer answers.

This final prompt should produce a decision record, not another speculative calculation. If a crucial question remains open, keep it on the list.

What a good answer looks like

Suppose your current label is known but its sizing system is not. The correct next step is to confirm the system with the brand or retailer. A useful Claude response says what is missing, points to the exact chart note and drafts a question. It does not silently convert the label and announce a perfect size.

If an actual try-on reveals discomfort, treat that observation as more important than an elegant table. Return to the relevant fitter or retailer with the record. The workflow is designed to make the conversation clearer; it is not a physical fitting service.

Frequently asked questions

Can Claude work as a bra size calculator?

It can explain supplied instructions and organise inputs. It cannot guarantee physical fit, and it should not invent a method.

Do UK and US cup labels always transfer directly?

Do not assume that. Use the applicable current retailer conversion information and preserve its notes.

Do I need to upload a photograph of myself?

No. Written chart extracts, garment identity and your own observations are enough for these prompts.

For broader preferences beyond sizing, use our lingerie shopping questions guide. Keep chart interpretation separate from choosing coverage, fastenings and styling.

Cover: AI-generated editorial concept. Fictional garments are not verified TRYBUY.IN inventory, product photographs or evidence of physical fit, comfort or performance.

Sources checked on 11 October 2026.