Free Medical Billing Calculators & Tools

Free Medical Billing Tools

Practical tools built by our billing team — the same math and letter structures we use when auditing practices and fighting denials. Everything runs instantly in your browser: no signup, no data sent anywhere, nothing stored. New tools are added regularly based on what billers ask us for.

Patient Responsibility Calculator

Combine copay, deductible, and coinsurance — with out-of-pocket max handling — to see exactly what the patient owes on any claim.

Medical Bill Negotiation Letter Generator

Professional letters for patients in seconds — itemized bill requests, financial assistance, payment plans, settlements, and EOB disputes.

Copay Calculator

Quick per-visit copay math for front-desk collection at check-in.

Coinsurance Calculator

Split any allowed amount between plan and patient at any coinsurance rate.

Denial Cost Calculator

Find out what claim denials really cost your practice every year — including rework labor.

Days in A/R Calculator

Measure how fast charges turn into cash and compare against industry benchmarks.

POS Code Decision Tree

Two questions and you have the right place of service code — plus whether it pays the facility or non-facility rate.

MPPR Calculator

Multiple Procedure Payment Reduction — enter your fee schedule amounts and see the 100/50/50 sequence and what it costs.

Underpayment Calculator

Compare the allowed amount on your remittance against your contracted rate — and see what the gap costs across a year.

Claim Frequency & Resubmission Code Tool

Corrected claim or void? Get code 7, 8 or 1, where it goes on the CMS-1500 or UB-04, and the control number that stops it rejecting.

Medicare Sequestration Calculator

The exact 2% reduction, what Medicare actually pays, and why the cut is 1.6% of the allowed amount — not 2%.

Who Pays First? COB Tool

Answer a few questions and get the coordination of benefits order — birthday rule and Medicare Secondary Payer rules included.

Therapy Threshold & KX Calculator

Check whether therapy charges have crossed the Medicare KX modifier threshold, how much headroom is left, and if targeted review applies.

8 Minute Rule Calculator

Enter therapy treatment minutes — get billable units under the Medicare 8 minute rule or the AMA Rule of Eights, plus the full chart.

Global Period Calculator

Surgery date plus global indicator — get the window, and the modifier that unlocks billing inside it.

Modifier Decision Tree

Answer up to three questions and get the correct CPT modifier — 25, 59, X{EPSU}, 50, 76, 77, 91, 26/TC or LT/RT.

Appeal Deadline Calculator

Enter the remit date and payer — get the exact appeal deadline and days remaining, before the window closes.

Timely Filing Deadline Calculator

Enter a date of service and payer limit — get the exact filing deadline and days remaining.

Appeal Letter Generator

Professional appeal letters for 8 denial scenarios, assembled from your claim details in seconds.

Gross Collection Rate Calculator

Get your GCR and see net collection rate beside it — the two numbers tell very different stories.

Net Collection Rate Calculator

Enter payments, charges, and contractual adjustments to see how much entitled revenue your practice actually collects.

RVU Calculator

Estimate the Medicare allowable from work, practice expense, and malpractice RVUs with GPCIs and the conversion factor.

Denial Rate Calculator

Enter claims submitted and denied to benchmark your denial rate against the 5% standard — and see the annual revenue riding on the gap.

BMI & ICD-10 Z-Code Calculator

Enter height and weight to get the BMI, the obesity class, and the exact Z68 diagnosis code for the claim.

Anesthesia Billing Calculator

Base units + exact-decimal time units + modifying units, times your conversion factor — the anesthesia allowable in seconds.

AR Aging Analyzer

Enter your four aging buckets to get percentages, benchmark verdicts, and the dollars decaying in the over-90 column.

E/M Code Level Calculator

Set the problems, data, and risk levels and get the office-visit code (99202–99215) the AMA 2-of-3 MDM rule supports — with the reasoning.

Want a tool that doesn't exist yet? Tell us what would help your billing day — we build these based on requests.

Frequently Asked Questions

Are these tools really free?

Yes — every tool runs entirely in your browser with no signup, no limits, and no data collection. They're built by our billing team as a resource for the billing community (and yes, we hope you'll think of us when you need full billing support).

Do the tools store or transmit my numbers or patient details?

No. All calculations and letter generation happen locally in your browser using JavaScript — nothing you type is sent to our servers or anyone else's. Refreshing the page erases everything.

Can I rely on these for exact patient billing or legal deadlines?

They implement standard plan logic and industry conventions, but plans and contracts vary — always verify against real eligibility data, your executed contracts, and actual EOBs. Treat results as strong working estimates.

Medical Billing Tools