Cash plus calculator
Designed and launched a Cash Plus APY calculator with dynamic presets and a $3K quick-select; A/B testing increased initial contributions by 13.8%.
Client
Vanguard
Services
Product Design
Experimentation
Duration
5 Weeks
At a glance
•Problem: Investors needed a clearer way to understand potential earnings and choose a confident starting contribution—without adding friction to a high-trust flow.
• Role: Led product design + interaction design; partnered with Product, Engineering, Analytics, and Content.
• Solution: A lightweight APY calculator with dynamic presets, a $3K quick-select, and clarity-first hierarchy to support faster decisions.
• Validation: A/B tested key patterns (preset strategy + quick-select) and iterated based on results and implementation constraints.
Summary
I designed a Cash Plus APY calculator that helps investors quickly understand “what my money could do” and choose a starting contribution with less hesitation. The experience balances simplicity with decision support through dynamic presets and clear, compliant guidance—improving outcomes without turning the flow into a multi-step detour.
Top Metrics
+23% increase in Cash Plus account openings (post-launch)
+13.8% lift in average initial contributions (post-launch)
A/B test (quick-select presets vs. input-only baseline):
$1K preset: contribution volume 24.8% → 26.9% with 27.8% CTR
$3K preset: higher adoption than $1K and helped more clients cross the Guided Choice advice-eligibility threshold, expanding the advice-qualified customer base
Shipped: preset contribution buttons + inline APY calculator that converts rate into real-time projected earnings at decision time
The Problem
Despite a competitive interest rate, new Cash Plus applicants weren’t funding their accounts during onboarding—and when they did, funding levels fell below business targets. Diagnostic research pointed to two barriers that reduced confidence and suppressed early funding:
• Underplayed value proposition: The experience didn’t clearly communicate the upside of a high-yield Cash Plus account, so investors didn’t feel a strong reason to choose it over alternatives.
• No guidance on contribution amounts: Investors had little direction on how much to deposit at account open, creating hesitation and decision friction.
the impact
• Launched the Cash Plus calculator and funding improvements, contributing to a +23% increase in Cash Plus account openings and a +13.8% lift in average initial contributions.
• Proved the impact of guided funding choices through a data-driven A/B test that compared the baseline input-only funding flow against two quick-select button variants featuring $1K and $3K presets.
• The $1K preset increased contribution volume from 24.8% → 26.9% and earned a 27.8% click-through rate (CTR)—showing that a lightweight default meaningfully reduces hesitation.
• The $3K preset attracted more clients and helped more investors cross Vanguard’s Guided Choice advice-eligibility threshold, expanding the advice-qualified customer base (and reinforcing that the “right” preset isn’t just about conversion—it can unlock downstream value).
• Introduced data-informed preset contribution options (e.g., $1K, $3K, $5K, $10K) to remove guesswork and fast-track decisions across different account needs and comfort levels.
• Added an inline APY calculator that translates each selection into real-time projections of annual earnings and total savings—turning an abstract interest rate into tangible dollar impact at the exact moment users decide whether to fund.
What drove the lift: The redesigned funding step pairs decision support (presets + quick-select) with value clarity (inline earnings projections). That combination reduces “how much should I deposit?” friction while making the benefit of funding feel concrete—improving funding behavior without adding extra steps or turning onboarding into a heavy calculator workflow.
