Cash plus calculator
Developed a dynamic interactive calculator to show potential interest earnings on initial contributions. Providing clearer insights and leading to a 23% boost in Cash Plus account openings and 3% decrease in fallout during account funding.
Client
Vanguard Financial
Industry
Financial Technology
Service
Product Design
UX Strategy
Duration
5 Weeks
Vanguard aimed to boost participation and size—of initial deposits during Cash Plus account opening. I led the end‑to‑end creation of an interactive APY calculator and preset contribution controls that turned abstract interest math into tangible dollar benefits.
The challenge
Despite a competitive interest rate, new Cash Plus applicants were not funding their account during onboarding, and even those who did contributed, it fell well below business targets. Diagnostic research revealed two primary barriers. Together, these factors eroded user confidence and suppressed early funding:
The solution
To overcome these barriers, I redesigned the funding step around two complementary elements. First, data‑driven preset contribution buttons based on different account types ($1 k, $3 k, $5 k, $10 k,) removed guesswork and fast‑tracked decision‑making. Second, an inline APY calculator translated each selection into real‑time projections of annual earnings and total savings, turning abstract interest rates into tangible dollar gains.
The design process
Before committing to a final solution, I developed two distinct design concepts and ran them through rapid iteration cycles:
Concept A – Dynamic slider calculator: A visually rich slider let users drag to choose a deposit amount while the earnings projection updated in real time. It excelled at conveying the “money grows as you slide” story but added complexity on smaller screens.
Concept B – Streamlined calculator: A minimalist card with four quick‑select buttons and an inline earnings readout that optimised tap speed and cognitive load.
Comparative usability testing showed the streamlined approach delivered faster task completion with equal comprehension, so we moved forward with Concept B—while capturing the slider’s emotional punch for future personalization ideas.
the results
The Cash Plus calculator launch drove a 23 % increase in cash account openings and a 13.8 % lift in average initial contributions. The initial contribution quick-select buttons proved especially powerful—leveraging a data-driven A/B test comparing our baseline input-only flow against two button variants that surfaced $1K and $3K presets. The $1K button bumped contribution volume from 24.8 % to 26.9 % (27.8 % CTR). More clients gravitated to the $3K option, crossing Vanguard’s Guided Choice advice-eligibility threshold and expanding the advice-qualified customer base.
