Pregnancy dating
Calculate gestational age and EDD from LMP, ultrasound, IUI/conception, or Day-3 and Day-5 IVF transfer—with Gregorian and Hijri dates shown together.
- LMP
- Ultrasound
- IUI
- IVF
Built with OB/GYN clinicians
Built by OB/GYN clinicians
Clinical calculations, organized
Obstetric decisions,
made clearer.
From pregnancy dating to fetal assessment, labour planning, medication support, and clinical handoff—ObiCalc keeps the numbers, context, and evidence within reach.
✓ For licensed healthcare professionals
✓ Built around real clinical workflow
✓ References close to every tool
TodayThursday, 30 July 202616 Safar 1448 AH
Dating methodsLMP · US · IUI · IVF
Fresh capture from iPhone Simulator
Live ObiCalc demonstration
A real pregnancy timeline, calculated every day.
The example advances automatically with the calendar. The gestational-age wheel always shows the real calculation; the Booking Planner lets you explore another pregnancy date without changing it.
Wed, 29 Jul 2026
15/02/1448
GregorianHijri
25 / Jan / 2026
Gestational Age
0 Weeks + 0 Days
Extremely Preterm
●2nd Trimester
Last Menstrual Period
Sun
25/01/2026
06/08/1447
Expected Delivery Date
Sun
01/11/2026
20/05/1448
Booking Planner
Slide → to preview a future date
26 wk 3 d
Wed, 29 Jul 202615/02/1448
26w 3d
Wed, 29 Jul 2026
· 15/02/1448
6.1Months
94Days to EDD
66%Pregnancy complete
Live example
Anchored to an LMP of 25 Jan 2026. The calculation updates at local midnight.
Interactive presentation reproduced from ObiCalc’s gestational-age wheel and Booking Planner.
One clinical workspace
Less searching.
More clinical focus.
ObiCalc brings high-frequency obstetric calculations and specialist decision-support tools into a consistent, calm interface—so the workflow stays familiar even when the clinical question changes.
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Clinical calculators
Purpose-built tools across screening, maternal health, fetal assessment, labour, neonatal care, medication, and everyday utilities.
See the full directory →+
Patient workflow
Save selected patient records, revisit recent calculations, organize favourites, and keep the next clinical step close at hand.
Explore workflow →PDF
Clear clinical reports
Generate polished mobile or A4 clinical reports in multiple languages, with patient context, dating basis, gestational age, EDD, antenatal plan, and an ObiCalc header.
See reporting →The complete toolkit
Every tool, professionally organized.
More than 25 focused add-ons sit beside the four core dating methods. Search, favourite, and reopen recent tools without navigating a maze of unrelated menus.
App category
Early Pregnancy & Screening
- Pre-eclampsia Risk
- First-Trimester Screening
- β-hCG Doubling
- MTX Dosing
App category
Maternal Health
- BMI Calculator
- Contraception & HRT
- VTE Risk Assessment
- OGTT Interpreter
- Preterm Labour Risk
- Edinburgh Postnatal Depression Scale
- Anti-D / Kleihauer
- Magnesium Sulfate Monitoring
App category
Fetal Assessment & Therapy
- MCA-PSV
- UA Doppler
- Timing of Delivery
- Biophysical Profile
- Diaphragmatic Hernia
- Skeletal Dysplasia
- Twin Discordance & TTTS staging
- Fetal Weight Centile
- Intrauterine Transfusion
App category
Labour & Delivery
- Bishop Score
- VBAC Success Rate
- Oxytocin Augmentation
- ECV Success Rate
- GBS Prophylaxis
App category
Neonatal
- Apgar Score
- Umbilical Cord Blood Gas
App category
Utilities
- Hijri ↔ Gregorian Date Converter
- Unit Converter
- Anion Gap
Also included: clinical references and validation notes, calculation search, favourites, recent tools, offline core calculations, dark mode, haptic feedback, font-size controls, Hijri display preferences, and account/subscription controls.
Designed around the work
A calculator is useful.
A workflow is better.
Save what matters. Reopen it quickly.
Authenticated clinicians can keep selected patient records with dating method, LMP, EDD, gestational age, record details, and short follow-up context.
MH
Patient record29 weeks + 3 days
Open →
Reports shaped like summaries, not screenshots.
Choose mobile or A4 output, add patient and antenatal context, then share or print through the device’s secure system.
Gestational age29w + 3dEDD13 Sep 2026
Evidence and responsibility stay visible.
Formulas, thresholds, published references, validation notes, and medical-disclaimer context remain close to the tool—never buried in a generic help page.
References & validationSource context near the calculation
✓Clinical depth, made visible
Not just a result.
A clearer clinical next step.
Real ObiCalc screens show how inputs become structured interpretation, evidence, alerts, and an output designed to be used—not decoded.
01 / 05 · Real app screens
Turn serial values into a trend clinicians can interpret.
ObiCalc calculates doubling time and percentage change, classifies the trajectory, and keeps the expected ranges and source context on the same screen.
See weight discordance and severity at a glance.
Two estimated fetal weights become a visual distribution, a discordance percentage, and structured staging context that supports faster review.
Complex fetal transfusion planning, presented with guardrails.
MCA-PSV, haemoglobin, fetal weight, and donor haematocrit come together in one calculated volume—with severity framing, warnings, and a transparent breakdown.
Patient-facing screening across languages.
The validated EPDS workflow separates patient-facing language from clinical interpretation, while keeping screening limitations and self-harm review guidance explicit.
Convert bedside factors into an evidence-based prediction.
The Burgos scoring factors remain visible beneath the prediction, so the final percentage is clear, explainable, and easy to discuss.
ObiCalc on your phone
Clinical clarity,
where the work happens.
Download ObiCalc on Google Play. The iPhone version is already reserved in App Store Connect and is currently under review.
Under review
A 7-day trial and monthly or annual subscription options are presented in the official store listing. Store pricing and availability may vary by region.
Version 1.3.5
A distinct app from the ObiCalc teamHijri ANC
Pregnancy dating in two calendars
Built for clinicians who work in Hijri and Gregorian.
Focused pregnancy dating from LMP, ultrasound, conception/IUI, and IVF—plus BMI, Bishop, Apgar, and date conversion. Private by design, with calculations processed on the device.
Fresh capture from iPhone Simulator
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Clinical responsibility
Decision support—not a substitute for judgment.
ObiCalc is intended for qualified healthcare professionals. Always verify calculations, assess the patient directly, and follow institutional protocols and current local guidance.