Clyven
Master the science of down insulation—calculate fill weights, measure loft, and build outdoor gear with engineering accuracy.
Download ClyvenInstant access to precision down-fill calculation tools
Master the science of down insulation—calculate fill weights, measure loft, and build outdoor gear with engineering accuracy.
Download ClyvenInstant access to precision down-fill calculation tools
Access specialized tools designed for hand-builders and cottage manufacturers creating custom down-insulated equipment.
All features included offline. No subscription or internet connection required. Compatible with iOS devices running version 1.2.
Every tool you need to design, construct, and verify down-insulated outdoor equipment.
Determine precise grams of down per baffle for sleeping bags, quilts, puffer jackets, vests, duvets, and booties using temperature-driven algorithms.
Measure achieved loft by photographing your piece next to a reference card of known height. One photograph delivers accurate results.
Run nine automated checks including under-fill analysis, down leakage detection, and fill power verification against design specifications.
Track completed builds over time with full data retention. Monitor loft degradation and performance metrics across your gear collection.
Back-solve from target comfort temperature to required insulation loft. Accounts for fabric permeability, baffle design, and fill material properties.
All calculations and measurements work without internet access. No account registration or cloud sync required for full functionality.
From concept to finished gear, Clyven guides you through every measurement and calculation.
Input your target comfort temperature and select from six shell fabrics with documented air permeability values. Choose one of eight baffle construction methods ranging from sewn-through to advanced V-baffle designs. The LoftEngine calculates required loft height and translates that into exact fill weight per chamber using your chosen material from the database of 12 real-world down specifications.
Monitor progress as you build with integrated kit lists and construction phase tracking. The app maintains running totals of down usage across all baffles, alerting you to discrepancies between planned and actual fill amounts in real time.
After construction, use the Loft Meter to photograph your piece with a reference card. The app measures achieved loft and compares it against design specifications. Archive completed projects with full environmental data, temperature ratings, and material details for future reference and performance tracking.
Understand the complete workflow from material selection through final quality verification.
Clyven was built for the cottage gear manufacturing community and serious DIY outdoor enthusiasts who demand precision in down-fill calculation. The app prioritizes offline functionality and data privacy with zero account requirements, no cloud dependencies, and complete local operation. All material specifications derive from industry-standard testing methods including IDFB and EN 12934 protocols. Version 1.2 represents refinements to the LoftEngine calculation system and expanded baffle construction support based on builder feedback.
iOS · Offline-capable · Version 1.2 · No subscription required
Download ClyvenFull offline functionality. No ads or in-app purchases. Optimized for hand-builders and small-batch manufacturers of down-insulated gear.